Simulation of visual impairment in persons with normal vision for scientific research.

Simulation of visual impairment in healthy eyes has multiple applications in students' training, research and product development. However, due to the absence of an existing standard protocol, the method of simulation was left to the discretion of the researcher. This review aimed to outline the various methods of simulating visual impairment and categorising them. A scoping review of the relevant publications was conducted. Of the 1593 articles originally retrieved from the databases, 103 were included in the review. The characteristics of the participants, the method for simulation of the visual impairment in persons with normal vision and the level or type of visual impairment that was simulated were extracted from the papers. None of the methods of simulation can be judged as being superior to the others. However, electronic displays produced the most consistent form of visual impairment simulation.

The effect of filters and varying illumination on contrast sensitivity in eyes with moderate to severe visual impairment.

PURPOSE: To investigate the effect of filters and illumination on contrast sensitivity in persons with cataract, pseudophakia, maculopathy and glaucoma to provide a guide for eye care providers in low vision rehabilitation. MATERIALS AND METHODS: A within-subjects experimental design with a counter-balanced presentation technique was employed in this study. The contrast sensitivity of eyes with cataract, pseudophakia, maculopathy and glaucoma was measured with filters (no filter, yellow, pink and orange) combined with increasing illumination levels (100 lx, 300 lx, 700 lx and 1000 lx) using the SpotChecks™ contrast sensitivity chart. The data were analyzed using descriptive statistics and two-way repeated measures ANOVA. RESULTS: The yellow filter at 100 lx significantly improved contrast sensitivity in the maculopathy group. There were no significant improvements with either intervention in the rest of the groups. There was, however, a significant interaction between filters and illumination in the cataract group. CONCLUSION: There were small improvements in contrast sensitivity at low illumination levels with the yellow filter in the maculopathy group, and this could be considered in clinical practice and low vision rehabilitation. Overall, filters at most illumination levels did not benefit most groups.

Case Series: Avoidable Blindness after Inappropriate Ophthalmic Self-medication in Ghana.

SIGNIFICANCE: Inappropriate ophthalmic self-medication continues to plague Sub-Saharan Africa because of lack of public health education and inaccessibility to eye care services. This case series describes three cases of blindness (two monocular, one binocular) in Ghana, because of self-treatment of ocular conditions using improper drugs or homemade herbal mixtures. The article highlights the consequences of misinterpretation of symptoms and use of traditional home remedies, leading to delayed professional eye care and avoidable blindness. PURPOSE: This case series aims to report three separate cases of avoidable blindness after inappropriate ophthalmic self-medication to draw attention to the need for intense public health education in Ghana. CASE REPORTS: Three men aged 25, 79, and 35 years, respectively, reported severe reduction in visual acuity in one eye for two cases and both eyes for one case. All patients reported ophthalmic self-medication either with an inappropriate drug bought from the drug store or a homemade herbal mixture made from leaves assumed to treat eye infections. Professional care did not yield any improvement in visual acuity because their corneas were already decompensated at the onset of management. The eye of one patient had to be enucleated. CONCLUSIONS: These cases highlight the importance of eye health promotion and education. It is recommended that intense sensitization is carried out at all levels.