Can children measure their own vision? A comparison of three new contrast sensitivity tests.

PURPOSE: To investigate the feasibility of children measuring their own contrast sensitivity using a range of tablet- and paper-based tests. METHODS: Forty children aged 5-15 years with amblyopia (N = 10), bilateral vision impairment (N = 10) or good vision (N = 20) measured their own vision on a screen-based optotype test (Manifold), a gamified vision test (PopCSF) and a paper-based test (Spotchecks) in a laboratory with minimal supervision. Completion rate, test-retest repeatability, test duration and participants' preferences were recorded for each test. RESULTS: Most participants (36/40) were able to perform all three tests. All tests were correlated with clinically measured visual acuity and contrast sensitivity (p < 0.001). The 95% coefficient of repeatability was 0.30 dB for Manifold, 0.29 dB for PopCSF and 0.13 dB for Spotchecks. All tests differentiated between children with reduced contrast sensitivity and control participants. PopCSF and Spotchecks were also able to differentiate between children with amblyopia and those with good vision. Median test time was 152, 130 and 202 s for Manifold, PopCSF and Spotchecks, respectively. Twenty-two participants preferred the PopCSF test, 10 preferred Spotchecks and 6 preferred Manifold. Thirty-nine out of the 40 children (98%) said they would measure their own vision at home using at least one of these tests every month. CONCLUSIONS: Children and young people can test their own contrast sensitivity with repeatable results. Of these three tests, the most repeatable was Spotchecks, the quickest was PopCSF and participants' favourite was PopCSF. Nearly all of the participants said they would be willing to use at least one of the three tests at home.

The evolution of targeted cannibalism and cannibal-induced defenses in invasive populations of cane toads.

Biotic conflict can create evolutionary arms races, in which innovation in one group increases selective pressure on another, such that organisms must constantly adapt to maintain the same level of fitness. In some cases, this process is driven by conflict among members of the same species. Intraspecific conflict can be an especially important selective force in high-density invasive populations, which may favor the evolution of strategies for outcompeting or eliminating conspecifics. Cannibalism is one such strategy; by killing and consuming their intraspecific competitors, cannibals enhance their own performance. Cannibalistic behaviors may therefore be favored in invasive populations. Here, we show that cane toad tadpoles (Rhinella marina) from invasive Australian populations have evolved an increased propensity to cannibalize younger conspecifics as well as a unique adaptation to cannibalism-a strong attraction to vulnerable hatchlings-that is absent in the native range. In response, vulnerable conspecifics from invasive populations have evolved both stronger constitutive defenses and greater cannibal-induced plastic responses than their native range counterparts (i.e., rapid prefeeding development and inducible developmental acceleration). These inducible defenses are costly, incurring performance reductions during the subsequent life stage, explaining why plasticity is limited in native populations where hatchlings are not targeted by cannibalistic tadpoles. These results demonstrate the importance of intraspecific conflict in driving rapid evolution, highlight how plasticity can facilitate adaptation following shifts in selective pressure, and show that evolutionary processes can produce mechanisms that regulate invasive populations.

Are wearable electronic vision enhancement systems (wEVES) beneficial for people with age-related macular degeneration? A scoping review.

INTRODUCTION: Age-related macular degeneration (AMD) is the most common cause of irreversible visual impairment in the United Kingdom. It has a wide-ranging detrimental impact on daily living, including impairment of functional ability and quality of life. Assistive technology designed to overcome this impairment includes wearable electronic vision enhancement systems (wEVES). This scoping review assesses the usefulness of these systems for people with AMD. METHODS: Four databases (Cumulative Index to Nursing and Allied Health Literature, PubMed, Web of Science and Cochrane CENTRAL) were searched to identify papers that investigated image enhancement with a head-mounted electronic device on a sample population that included people with AMD. RESULTS: Thirty-two papers were included: 18 studied the clinical and functional benefits of wEVES, 11 investigated use and usability and 3 discussed sickness and adverse effects. CONCLUSIONS: Wearable electronic vision enhancement systems provide hands-free magnification and image enhancement producing significant improvements in acuity, contrast sensitivity and aspects of laboratory-simulated daily activity. Adverse effects were infrequent, minor and spontaneously resolved with the removal of the device. However, when symptoms arose, they sometimes persisted with continued device usage. There are multi-factorial influences and a diversity of user opinions on promotors to successful device use. These factors are not exclusively driven by visual improvement and incorporate other issues including device weight, ease of use and inconspicuous design. There is insufficient evidence of any cost-benefit analysis for wEVES. However, it has been shown that a user's decision to make a purchase evolves over time, with their estimates of cost falling below the retail price of the devices. Additional research is needed to understand the specific and distinct benefits of wEVES for people with AMD. Further patient-centred research should assess the benefits of wEVES in user-led activities when directly compared with alternative coping strategies, allowing professionals and users to make better prescribing and purchasing decisions.

Novel use of a Franklin split lens for cycling with hemianopia.

PURPOSE: Optical rehabilitation for hemianopia includes the prescription of partial aperture prismatic lenses. Fresnel lenses for this purpose have poor optical quality, while bonded lenses have poor cosmesis and can only be made in glass, creating a potential hazard. Here we present an alternative lens type, which does not reduce contrast sensitivity and which can be made in plastic materials. METHODS: A rotated Franklin split lens was prescribed for the right eye only to provide a full aperture prismatic lens without using a Fresnel prism or bonded lenses. Using different refractive indices in each lens provided a minimal transition in thickness and an acceptable cosmetic appearance. This lens was prescribed to a 34-year-old woman with homonymous right hemianopia. Her contemporaneous comments are presented. RESULTS: The rotated Franklin split lens provided 18Δ over the temporal edge of the lens. The wearer noticed chromatic aberration with this lens, but was able to cycle comfortably when wearing the lens without any reduction in contrast. CONCLUSIONS: A rotated Franklin split lens can be used for the optical rehabilitation of hemianopia. In this case study, cycling was possible with this lens.

Design considerations for the ideal low vision aid: insights from de-brief interviews following a real-world recording study.

PURPOSE: Low Vision Aids (LVAs) can have a transformative impact on people living with sight loss, yet the everyday requirements for developing such devices remain poorly understood and defined. This study systematically explored LVA requirements through a structured de-brief interview following a real-world self-recording study. The purpose of this work was to define the actual needs of those living with sight loss so that low vision services can better address them in future. METHODS: Thirty-two visually impaired volunteers with varying levels of previous LVA experience participated in a de-brief interview centred around a structured questionnaire. The de-brief followed a one-week real-world study during which participants used recoding spectacles to capture and narrate all situations in which they would use a 'perfect sight aid'. Content and thematic analyses were used to analyse interviews which had the purpose of contextualising these recordings and exploring requirements around psychological, functional and design factors. RESULTS: Participants reported that 46% of tasks which they had recorded were most important to them. Of these tasks, 82% were encountered frequently. Few tasks emerged as very important across many participants, the remaining tasks reflecting individual lifestyles or circumstances. Every participant used at least one LVA in their everyday life and 72% identified further coping strategies. Current LVAs identified as consistently poor were distance LVAs, with all other devices receiving mixed or only positive feedback. Around two-thirds of participants would prefer LVA use on an ad-hoc / quick access basis rather than over long periods of time, and just over half would prefer to carry it rather than wearing it all day. Lack of consistency in these responses illustrated potentially different user clusters with divergent design needs. Two-thirds of participants emphasised the desire for a discreet LVA that does not attract attention. However, since half of all participants felt self-conscious in public or in front of other people when wearing the small recording spectacles, this may not be technically achievable. CONCLUSIONS: There is a substantial opportunity for new LVAs to address visual needs that traditional devices and coping strategies cannot support. Functional, psychological and design factors require careful consideration for future LVAs to be relevant and widely adopted.

Lockdown low vision assessment: an audit of 500 telephone-based modified low vision consultations.

PURPOSE: Non-urgent face-to-face outpatient ophthalmology appointments were suspended in the United Kingdom in March 2020, due to the COVID-19 outbreak. In common with other centres, Moorfields Eye Hospital NHS Foundation Trust (London) offered modified telephone consultations to new and follow-up patients in the low vision clinic. Here we assess the success of this telephone service. METHODS: Data were collected for 500 consecutive telephone low vision appointments. Successful completion of the assessment and clinical outcomes (low vision aids prescribed, onward referral) were recorded. RESULTS: Telephone assessments were completed for 364 people (72.8%). The most common reasons for non-completion were either no answer to the telephone call (75 people, 15%), or the patient declining assessment (20 people, 4%). There was no association between age and the likelihood of an assessment being completed. 131 new low vision aids were dispensed, 77 internal referrals were made and 15 people were referred to outside services. More than 80% of the low vision aids prescribed were useful. CONCLUSIONS: Telephone low vision assessments were completed in about three-quarters of cases. About one-quarter of consultations resulted in new low vision aids being dispensed, which were generally found useful. Telephone low vision assessments can be used successfully in a large low vision clinic, but have many limitations when compared to face-to-face assessments.

Online Survey of Digital Reading by Adults with Low Vision.

SIGNIFICANCE: Access to digital text is increasingly widespread, but its impact on low-vision reading is not well understood. PURPOSE: We conducted an online survey of people with low vision to determine what assistive technologies they use for visual reading, their preferred text characteristics, and the time they devote to reading digital and hard-copy text. METHODS: One hundred thirty-three low-vision participants completed an online survey. Participants reported the nature and history of their low vision, their usage of different assistive technologies, and time devoted to five visual reading activities. RESULTS: The three largest diagnostic categories were albinism (n = 36), retinitis pigmentosa (n = 20), and glaucoma (n = 15). Mean self-reported acuity was 0.93 logMAR (range, 0.1 to 1.6 logMAR). Mean age was 46 years (range, 18 to 98 years). Participants reported on percentage time spent reading using vision, audio, or touch (braille). Seventy-five percent of our participants did more than 50% of their reading visually. Across five categories of reading activities-work or education, news, pleasure, spot reading, and social networking-participants reported more time spent on digital reading than hard-copy reading. Eighty-nine percent of our participants used at least one technology from each of our two major categories of assistive technologies (digital content magnifiers and hard-copy content magnifiers) for visual reading. CONCLUSIONS: Despite the growing availability of digital text in audio or braille formats, our findings from an online sample of people with low vision indicate the continuing importance of visual reading. Our participants continue to use technology to access both hard-copy and digital text, but more time is devoted to digital reading. Our findings highlight the need for continued research and development of technology to enhance visual reading accessibility.

Everyday visual demands of people with low vision: A mixed methods real-life recording study.

Research has demonstrated that low vison aids (LVAs) can have a positive impact on the functional sight of those living with sight loss. Step changes in technology are now enabling new wearable LVAs with greater potential than those available previously. For these novel devices to receive increased acceptance and therefore adoption by those with sight loss, visual task demands have to be understood more clearly in order to enable better alignment between device design and user requirements. The aim of this study was to quantify these requirements. Thirty-two participants aged 18 to 87 wore a spectacle-mounted video camera to capture and narrate all everyday situations in which they would use a "perfect" sight aid during 1 week. Captured scenes were analyzed through categorization and computational image analysis. Results showed large variation in activities and lifestyles. Participants reported no available sight aid or coping strategy for 57% of the recorded activities. Reading made up 49% of all recorded tasks, the other half comprising non-textual information. Overall, 75% of captured activities were performed ad hoc (duration of 0-5 minutes), 78% occurred indoors, 58% occurred at home, 48% were lit by natural light, 68% included the object of interest within reach, and 69% required a single focus plane only. Around half of captured objects of interest had a size of 2 degrees visual angle (2.08 logarithm of the minimum angle of resolution [logMAR]) or smaller. This study highlights the need for a sight aid that can make both textual and non-textual scenes accessible while offering flexibility to accommodate individual lifestyles.

The Effects of Conspecific Alarm Cues on Larval Cane Toads (Rhinella marina).

Many aquatic organisms detect and avoid damage-released cues from conspecifics, but the chemical basis of such responses, and the effects of prolonged exposure to such cues, remain poorly understood. Injured tadpoles of the cane toad (Rhinella marina) produce chemical cues that induce avoidance by conspecific tadpoles; and chronic exposure to those cues decreases rates of tadpole survival and growth, and reduces body size at metamorphosis. Such effects suggest that we might be able to use the cane toads' alarm cue for biocontrol of invasive populations in Australia. In the present study, we examined behavioral and ecological effects of compounds that are present in cane toad tadpoles and thus, might trigger avoidance of crushed conspecifics. Four chemicals (L-Arg, L-Leu-L-Leu-OH, L-Leu-L-Ile-OH and suberic acid) induced behavioral avoidance in toad tadpoles at some (but not all) dosage levels, so we then exposed toad larvae to these chemicals over the entire period of larval development. Larval survival and size at metamorphosis were decreased by chronic exposure to crushed conspecifics (consistent with earlier studies), but not by exposure to any of the four chemicals. Indeed, L-Arg increased body size at metamorphosis. We conclude that the behavioral response to crushed conspecifics by cane toad tadpoles can be elicited by a variety of chemical cues, but that consistent exposure to these individual chemical cues does not affect tadpole viability or developmental trajectory. The optimal behavioral tactic of a tadpole may be to flee if it encounters even a single chemical cue likely to have come from an injured conspecific (indicative of predation risk), whereas the continuing presence of that single chemical (but no others) provides a less reliable signal of predation risk. Our data are consistent with results from studies on fish, that suggest a role for multiple chemicals in initiating alarm responses to damage-released cues.

Benefit of an electronic head-mounted low vision aid.

PURPOSE: To evaluate the efficacy of electronic head-mounted low vision aid (e-LVA) SightPlus (GiveVision, UK, givevision.net) and to determine which people with low vision would see themselves likely using an e-LVA like this. METHODS: Sixty participants with low vision aged 18 to 93 used SightPlus during an in-clinic study session based on a mixed methods design. Visual acuity (ETDRS), contrast sensitivity (Pelli-Robson) and reading performance (MNREAD) were measured binocularly at baseline (no device), with the device in 'normal' mode (zoom only), and with preferred enhanced mode (zoom and one of four digital image enhancements). At the end of the session, a short questionnaire recorded willingness to use an e-LVA like SightPlus, potential use cases, positive/negative comments and adverse effects. RESULTS: Binocular distance visual acuity improved significantly by 0.63 logMAR on average (p < 0.0001) to 0.20 logMAR. Contrast sensitivity improved significantly by 0.22 log units (p < 0.0001) to 1.21 log units with zoom only and by 0.40 log units to 1.37 log units with zoom and preferred image enhancement. Reading performance improved significantly for near visual acuity and critical print size (p < 0.015), although reading speed significantly decreased (p < 0.0001). Nearly half (47%) of the participants indicated they would use an e-LVA like SightPlus, especially for television, reading and entertainment (e.g. theatre). Multivariate logistic regression showed that proportion of lifetime affected by sight loss, baseline contrast sensitivity and use of electronic LVAs explained 41% of the variation in willingness to use. CONCLUSIONS: SightPlus improves visual function in people with low vision and would be used in its current form by one half of the people who tried it. Adverse effects were infrequent and resolved when the device was removed. Future work should focus on comparing e-LVAs through repeatable real-world tasks and impact on quality of life.

Transplantation of Human Embryonic Stem Cell-Derived Retinal Pigment Epithelial Cells in Macular Degeneration.

PURPOSE: Transplantation of human embryonic stem cell (hESC)-derived retinal pigment epithelial (RPE) cells offers the potential for benefit in macular degeneration. Previous trials have reported improved visual acuity (VA), but lacked detailed analysis of retinal structure and function in the treated area. DESIGN: Phase 1/2 open-label dose-escalation trial to evaluate safety and potential efficacy (clinicaltrials.gov identifier, NCT01469832). PARTICIPANTS: Twelve participants with advanced Stargardt disease (STGD1), the most common cause of macular degeneration in children and young adults. METHODS: Subretinal transplantation of up to 200 000 hESC-derived RPE cells with systemic immunosuppressive therapy for 13 weeks. MAIN OUTCOME MEASURES: The primary end points were the safety and tolerability of hESC-derived RPE cell administration. We also investigated evidence of the survival of transplanted cells and measured retinal structure and function using microperimetry and spectral-domain OCT. RESULTS: Focal areas of subretinal hyperpigmentation developed in all participants in a dose-dependent manner in the recipient retina and persisted after withdrawal of systemic immunosuppression. We found no evidence of uncontrolled proliferation or inflammatory responses. Borderline improvements in best-corrected VA in 4 participants either were unsustained or were matched by a similar improvement in the untreated contralateral eye. Microperimetry demonstrated no evidence of benefit at 12 months in the 12 participants. In one instance at the highest dose, localized retinal thinning and reduced sensitivity in the area of hyperpigmentation suggested the potential for harm. Participant-reported quality of life using the 25-item National Eye Institute Visual Function Questionnaire indicated no significant change. CONCLUSIONS: Subretinal hyperpigmentation is consistent with the survival of viable transplanted hESC-derived RPE cells, but may reflect released pigment in their absence. The findings demonstrate the value of detailed analysis of spatial correlation of retinal structure and function in determining with appropriate sensitivity the impact of cell transplantation and suggest that intervention in early stage of disease should be approached with caution. Given the slow rate of progressive degeneration at this advanced stage of disease, any protection against further deterioration may be evident only after a more extended period of observation.

How People with Low Vision Achieve Magnification in Digital Reading.

SIGNIFICANCE: Digital reading displays provide opportunities for enhancing accessibility of text for low vision. How are these displays used by people in their daily lives? PURPOSE: Subjects responded to an online survey concerning their vision history, reading technology, display preferences, and reading habits. Here, we report on findings concerning acuity and magnification. METHODS: The survey asked subjects to arrange a text passage for typical reading and to report viewing distance, screen dimensions, and the number of characters per line. Seventy-five adult subjects (most with early-onset low vision, few with central field loss) completed all survey questions relevant to the analysis of acuity and magnification. Mean acuity was .92 logMAR (range, 0.1 to 1.6), and mean age was 44.8 years (range, 18 to 71 years). Twelve normally sighted controls reported the same information while viewing the passage on cell phones, tablets, and computers. RESULTS: The controls had a mean viewing distance of 38.7 cm and a mean x-height of 1.38 mm. For all three types of devices, angular x-height was 0.21° (close to laboratory estimates of the critical print size for reading). Low vision subjects showed decreasing viewing distance and increasing print size with larger values of logMAR acuity. Most of the low vision subjects achieved their desirable magnification by a combination of reduced viewing distance and increased physical letter size. The majority (54 of 75) relied more on letter-size magnification. Relative to the controls, regression analysis revealed that a typical low vision subject with logMAR acuity of 1.0 reduced viewing distance by a factor of 2.8 and enlarged physical print size by a factor of 6. CONCLUSIONS: Our survey shows that people with a wide range of acuities are engaged in digital reading. Our subjects achieved desirable magnification primarily by enlarging physical character size and to a lesser extent by reducing viewing distance.

Randomized Trial of Tablet Computers for Education and Learning in Children and Young People with Low Vision.

SIGNIFICANCE: Mobile devices such as tablet computers have become widely available as mainstream devices and are also used in some schools, but there is an absence of robust information regarding the efficacy of any optical/electronic low vision device or tablet computer in supporting education of young people with low vision. PURPOSE: A randomized controlled trial (RCT) is needed to measure the impact of tablet computers on education, specifically on independent access to educational material, in children and young people with low vision. We conducted a pilot RCT to determine the feasibility of conducting a full-scale trial. METHODS: This was a randomized multicenter pilot trial across two sites in the United Kingdom and one site in India. Forty children and young people aged 10 to 18 years with low vision (best-corrected visual acuity for distance between <20/60 [0.48 logMAR] and 20/400 [1.30 logMAR] in the better eye) in the United Kingdom (n = 20) and India (n = 20) were randomized to two parallel arms, with a 1:1 allocation ratio, to control (n = 20) or intervention (n = 20). Control group participants received standard low vision care. The intervention group received a tablet computer (iPad) with low vision applications and instruction in its use, including accessibility features. Four primary outcomes included (1) 6-month recruitment rate, (2) retention of participants for 3 months, (3) acceptance/usage of device, and (4) accessibility of device. RESULTS: Nineteen participants (95%) enrolled within 6 months in the United Kingdom, and 20 participants (100%), in India. Retention at 3 months was 85% (n = 17) in the United Kingdom and 95% (n = 19) in India. More than one half of participants reported using a tablet computer at school at least once every day. The majority (90%) found it easily accessible. CONCLUSIONS: This study demonstrated that it is feasible to recruit children and young people with low vision into an international multicenter RCT of electronic assistive technology. Regardless of geographical location, children and young people with low vision reported using tablet computers at least once a day at school and accessed them easily.

The Pulfrich Phenomenon: Practical Implications of the Assessment of Cases and Effectiveness of Treatment.

The Pulfrich phenomenon, originally described in normal observers, is a treatable disorder of the perception of movement in depth in cases of unilateral or asymmetric optic neuropathy. Treatment is highly bespoke and factors influencing treatment response and failure remain unclear. We assessed 25 adults with suspected Pulfrich phenomenon due to a range of conditions in two tertiary referral centres. Monocularly tinted spectacles were successful in reducing symptoms of the Pulfrich phenomenon under daylight conditions in nine subjects, eight of whom had optic neuritis. These spectacles were not effective at night and in patients with visual field defects due to ischaemic optic neuropathy, glaucoma, optic disc drusen or severe peripapillary retinal nerve fibre loss on optical coherence tomography.

Functional visual fields: relationship of visual field areas to self-reported function.

PURPOSE: The aim of this study is to relate areas of the visual field to functional difficulties to inform the development of a binocular visual field assessment that can reflect the functional consequences of visual field loss. METHODS: Fifty-two participants with peripheral visual field loss undertook binocular assessment of visual fields using the 30-2 and 60-4 SITA Fast programs on the Humphrey Field Analyser, and mean thresholds were derived. Binocular visual acuity, contrast sensitivity and near reading performance were also determined. Self-reported overall and mobility function were assessed using the Dutch ICF Activity Inventory. RESULTS: Greater visual field loss (0-60°) was associated with worse self-reported function both overall (R2 = 0.50; p < 0.0001), and for mobility (R2 = 0.64; p < 0.0001). Central (0-30°) and peripheral (30-60°) visual field areas were similarly related to mobility function (R2 = 0.61, p < 0.0001 and R2 = 0.63, p < 0.0001 respectively), although the peripheral (30-60°) visual field was the best predictor of mobility self-reported function in multiple regression analyses. Superior and inferior visual field areas related similarly to mobility function (R2 = 0.56, p < 0.0001 and R2 = 0.67, p < 0.0001 respectively). The inferior field was found to be the best predictor of mobility function in multiple regression analysis. CONCLUSION: Mean threshold of the binocular visual field to 60° eccentricity is a good predictor of self-reported function overall, and particularly of mobility function. Both the central (0-30°) and peripheral (30-60°) mean threshold are good predictors of self-reported function, but the peripheral (30-0°) field is a slightly better predictor of mobility function, and should not be ignored when considering functional consequences of field loss. The inferior visual field is a slightly stronger predictor of perceived overall and mobility function than the superior field.

Can we control the invasive cane toad using chemicals that have evolved under intraspecific competition?

Many invasive species experience intense intraspecific competition, because they are abundant in anthropogenically disturbed habitats where few native species persist. Species-specific competitive mechanisms that evolve in this context may offer novel, highly targeted means to control invasive taxa. We conducted laboratory experiments to evaluate the feasibility of this method of control, based on waterborne cues that are produced by tadpoles of the cane toad (Rhinella marina) to suppress the development of conspecific embryos. Our trials examined the nature and species-specificity of the effect, the robustness of the cue to freezing and storage, and the amounts required to suppress toad embryos. Our results were encouraging. The cue appears to be chemical rather than a biological organism, and may well be species-specific; the four species of native anurans that we tested were not influenced by toad larval cues. The cue retains its effectiveness after being frozen, but not after being dried, or after 7 d in water. It is effective at very low concentrations (the amount produced by three tadpoles within 750 L of water). Overall, the cane toad's suppressor pheromone may offer an effective new way to control invasive toads.

Smartphone, tablet computer and e-reader use by people with vision impairment.

PURPOSE: Consumer electronic devices such as smartphones, tablet computers, and e-book readers have become far more widely used in recent years. Many of these devices contain accessibility features such as large print and speech. Anecdotal experience suggests people with vision impairment frequently make use of these systems. Here we survey people with self-identified vision impairment to determine their use of this equipment. METHOD: An internet-based survey was advertised to people with vision impairment by word of mouth, social media, and online. Respondents were asked demographic information, what devices they owned, what they used these devices for, and what accessibility features they used. RESULTS: One hundred and thirty-two complete responses were received. Twenty-six percent of the sample reported that they had no vision and the remainder reported they had low vision. One hundred and seven people (81%) reported using a smartphone. Those with no vision were as likely to use a smartphone or tablet as those with low vision. Speech was found useful by 59% of smartphone users. Fifty-one percent of smartphone owners used the camera and screen as a magnifier. Forty-eight percent of the sample used a tablet computer, and 17% used an e-book reader. The most frequently cited reason for not using these devices included cost and lack of interest. CONCLUSIONS: Smartphones, tablet computers, and e-book readers can be used by people with vision impairment. Speech is used by people with low vision as well as those with no vision. Many of our (self-selected) group used their smartphone camera and screen as a magnifier, and others used the camera flash as a spotlight.

Is binocular vision worth considering in people with low vision?

In someone with good vision, binocular vision provides benefits which could not be obtained by monocular viewing only. People with visual impairment often have abnormal binocularity. However, they often use both eyes simultaneously in their everyday activities. Much remains to be known about binocular vision in people with visual impairment. As the binocular status of people with low vision strongly influences their treatment and rehabilitation, it should be evaluated and considered before diagnosis and further recommendations.

Mechanisms, costs, and carry-over effects of cannibal-induced developmental plasticity in invasive cane toads.

Inducible defences can improve survival in variable environments by allowing individuals to produce defences if they detect predators. These defences are often expressed as inter-related developmental, morphological, and behavioural changes. However, producing defences can incur costs, which may be expressed immediately and/or during subsequent life stages. In Australia, waterborne cues of potentially cannibalistic conspecific tadpoles induce hatchlings of invasive cane toads to accelerate their developmental rate, thereby reducing their window of vulnerability. However, the mechanisms and costs of such accelerated development are poorly understood, and whether cane toad embryos show cannibal-induced plasticity in other traits is unknown. Here, we found no evidence of altered time of hatching for embryos exposed to non-feeding conspecific cannibal tadpole cues. Additionally, hatchling dispersal behaviours were not affected by exposure to these cues. However, developmental acceleration of hatchlings induced by exposure to tadpole cues was accompanied by reduced hatchling growth, indicating a trade-off between these processes. At the conclusion of the hatchling stage, cannibal-exposed individuals were smaller and morphologically distinct from control siblings. This size reduction affected performance during the subsequent tadpole stage: smaller cannibal-exposed individuals were more likely to die, and initial size tended to be positively associated with subsequent tadpole growth and development across treatments (respectively, p = .07 and p = .06). However, even accounting for variation in initial size, there was an additional negative effect of cannibal exposure on tadpole growth and development, demonstrating that the fitness costs associated with developmental acceleration are not entirely attributable to size reductions.

Eccentric Viewing Training for Age-Related Macular Disease: Results of a Randomized Controlled Trial (the EFFECT Study).

Purpose: Eccentric viewing training for macular disease has been performed for > 40 years, but no large studies including control groups have assessed the benefits of this training. The EFFECT (Eccentric Fixation From Enhanced Clinical Training) study is a large randomized controlled trial of 2 types of eccentric viewing training. Design: Randomized controlled trial. Participants: Two hundred adults with age-related macular disease. Methods: Participants were randomized to either of the following: (1) a control group; (2) a group receiving supervised reading support; (3) a group receiving 3 sessions of training to optimize the use of their own preferred retinal locus; or (4) a group receiving 3 sessions of biofeedback training of a theoretically optimal trained retinal locus. All participants received standard low-vision rehabilitation. Main Outcome Measures: The primary outcome was patient-reported visual task ability measured on the Activity Inventory instrument at goal level. Secondary outcomes included reading performance and fixation stability. Results: There was no difference between groups on change in task ability (F(3,174) = 1.48, P = 0.22) or on any of the secondary outcome measures. Visual acuity and contrast sensitivity fell in all groups, suggesting that disease progression outweighed any benefit of training. Conclusions: Eccentric viewing training did not systematically improve task ability, reading performance, or fixation stability in this study. Our results do not support the routine use of eccentric viewing training for people with progressing age-related macular disease, although this training may help people with end-stage disease. Rehabilitation of an inherently progressive condition is challenging. Financial Disclosures: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.