An investigation of low power convex lenses (adds) for eyestrain in the digital age (CLEDA).

INTRODUCTION: Digital eye strain (DES; computer vision syndrome) is a common cause of symptoms when viewing digital devices. Low-powered convex lenses (adds) have been recommended for the condition and "accommodative support" designs developed on this premise. The present research reports the extent to which dry eye is present in this population and the effect of convex lenses on symptoms and visual performance. METHODS: The CVS-Q instrument was used to select pre-presbyopic adults with the symptoms of DES. Participants received a full eye examination including an assessment of dry eye with a modified SANDE questionnaire and using DEWS I criteria. The immediate effect of low-powered convex lenses (low adds: +0.50D, +0.75D, +1.25D) was investigated using subjective preference and a double-masked comparison with plano lenses with the Wilkins Rate of Reading Test (WRRT). Throughout this testing, participants wore their full distance refractive correction, based on non-cycloplegic retinoscopy and subjective refraction. RESULTS: The signs and symptoms of dry eye were frequently present. Most participants reported a subjective preference for low adds, with +0.75D the most commonly preferred lens. Low adds (+0.50D and +0.75D; but not +1.25D) were associated with significantly improved performance at the WRRT. One quarter of participants read more than 10% faster with these additional convex lenses. CONCLUSIONS: The study population was aged 20-40y and mostly worked on desktop computers. It is possible that +1.25D add may be more advantageous for people who are older or work more at closer viewing distances. Many symptomatic users of digital devices report a preference for low adds and use of these lenses is often associated with an improvement in reading performance.

Digital Eye Strain in a Population of Young Subjects.

The main goal of our study was to prove short-term objective influence of near addition and relieving prism on accommodative and vergence facility in group of young healthy persons. Further, we wanted to prove objective and subjective difference between two types of soft contact lenses during working with digital device. We had in total 37 subjects in our study. The first group contained 37 subjects with average age 23 years without important eye pathology. The second group contained 8 subjects with the same average age without important eye pathology. In the first group of subjects, we measured binocular accommodative facility (BAF) and binocular vergence facility (BVF) with and without addition 1 D and with and without relieving prism 2 pD BO at working distance 45 cm. In the second group, we evaluated BAF, BVF and standardized questionnaire (Computer Vision Syndrome Questionnaire - CVS-Q, Sequí M. 2015) during usage of two types of soft contact lenses. The first type of contact lenses (type 1) contained relieving prism for PC working and type 2 was soft contact lens with aspheric design. In the first group of subjects, we measured these values: BAF without addition = 12.78 cpm, BAF with addition = 11.57 cpm, BVF without prism = 12.32 cpm, BVF with prism = 11.59 cpm. In the second group of subjects, we measured with contact lens type 1 these values: BAF = 12.13 cpm, BVF = 13.63 cpm and questionnaire score 9.43 points. With contact lens type 2 we measured BAF = 11.75 cpm, BVF = 11.63 cpm and questionnaire score 12.86 points. We proved statistically important different between two variable only in the first group between BAF with and without addition and BVF with and without relieving prism. In conclusion, we found statistically important decrease in variable BAF and BVF with usage of addition and relieving prism. We found that neither addition nor prism have positive influence on increase of BAF and BVF. Subjects in second group had higher BAF and BVF values with both types of contact lenses in comparison with natural values. We found that with contact lens type 1 (with addition) subjects had higher BAF and BVF values in comparison with contact lens type 2 (aspheric). Subjects with contact lens type 1 had also lower (better) questionnaire score, i.e. 9.43 versus 12.86 point. Key words: Digital eyestrain syndrome, accommodative and vergence facility, addition, relieving prism.

Effect of virtual reality headset wear on the tear film: A randomised crossover study.

PURPOSE: To compare the effects of virtual reality headset wear and conventional desktop computer display use on ocular surface and tear film parameters. METHODS: Twenty computer operators were enrolled in a prospective, investigator-masked, randomised crossover study. On separate days, participants were randomised to 40 min of continuous virtual reality headset wear or conventional desktop computer display use. Outer eyelid and corneal temperatures, tear film lipid layer grade, and non-invasive tear film breakup time were measured at baseline and immediately following the 40-minute exposure period. RESULTS: Virtual reality headset wear resulted in increases in outer eyelid (mean difference +0.5 ±â€¯0.6 °C; p < 0.001) and corneal temperatures (mean difference, +0.4 ±â€¯0.6 °C; p = 0.004), relative to conventional desktop computer display use. These increases were associated with significant improvements in tear film lipid layer grade (median difference, +1 grade; interquartile range, 0 to +2 grades; p < 0.001) and non-invasive tear film breakup time (mean difference, +7.2 ±â€¯12.4 s; p = 0.02). CONCLUSIONS: Clinically significant improvements in lipid layer thickness and tear film stability were observed with virtual reality headset wear, despite producing only modest increases in ocular temperatures relative to conventional desktop computer display use. These findings would suggest that virtual reality headset wear demonstrates potential for dry eye relief for computer operators in the modern workplace environment.