Does the optimal level of illumination improve both visual functions and visual comfort in schoolchildren with low vision?

Lighting modification is commonly performed by optometrists and occupational therapists to enhance visibility and visual comfort among schoolchildren with low vision. The purpose of this study is to determine the optimal illumination level for visual function and visual comfort of schoolchildren with low vision and the relationship between them. A cross-sectional study was conducted to assess five levels of illumination ranging from 125 lux to 2000 lux to determine the optimal illumination for visual functions and visual comfort in schoolchildren with low vision from a special education school for blind in Malaysia. Purposive sampling was done to recruit forty-two schoolchildren with low vision for this study. Visual functions assessed were visual acuity, measured using the Early Treatment Diabetic Retinopathy Study LogMAR chart at distance and near, contrast sensitivity (CS) measured using the Pelli-Robson chart at distance and the Mars CS chart at near. Reading speed was determined using the Universiti Kebangsaan Malaysia Malay Language Related Word Reading Text test chart. Subjects were asked to rate their visual comfort using a validated questionnaire at the end of each measurement of visual functions and reading speed for the different illumination levels. Visual acuity and contrast sensitivity at distance and near, visual comfort and reading speed improved significantly with increase in illumination levels (p<0.05). However, the interaction between illumination level and level of low vision was not significant (p>0.05). Visual comfort was significantly associated with visual function (p<0.05), while direct association between visual comfort and illumination level was not significant (p>0.05). Optimal illumination for improvement of visual function, reading speed and visual comfort range from 276.67 lux to 701.59 lux. Majority of the schoolchildren with low vision had improved visual function, reading speed and visual comfort with increased illumination. Illumination of at least 600 lux is recommended for maximum visual functioning and visual comfort of schoolchildren with low vision.

Double Eyelid Tape Wear Affects Anterior Ocular Health among Young Adult Women with Single Eyelids.

Many East Asians apply double eyelid tape to create the double eyelid effect temporarily as a means of increasing their beauty. This study evaluated the effects of four-week wear of double eyelid tape on anterior ocular health in young adult women with single eyelids. Twenty-nine participants who met the inclusion criteria were recruited. The participants' anterior ocular health was examined including blinking characteristics (blink pattern and blink rate), ocular surface health (presence of corneal abrasion, corneal staining, conjunctival staining, corneal curvatures, meibomian gland dysfunction), tear break up time, intraocular pressure, and subjective comfort level. Participants were required to apply the double eyelid tape for at least eight hours a day and five days a week for four weeks. The parameters were re-measured at the end of each week. There was a significant increase in conjunctival staining, corneal staining, and meibomian gland dysfunction, with a significant reduction in tear break-up time and intraocular pressure. By week 3, all participants had incomplete blinks. There was no significant change in symptoms and subjective comfort level reported. Therefore, patients and eye care practitioners should be aware of the potential implications of double eyelid tape wear on ocular health, with no significant change in subjective comfort.