More than one third of students were visually impaired for potentially avoidable reasons, indicating lack of eye health awareness and eye care services in the community. The cause of visual impairment remained unknown in a large number of students, which indicates the need for introduction of modern diagnostic tools.

A high proportion of students with low vision in integrated schools could benefit from optical intervention. A system of comprehensive eye examination at the time of school enrollment would allow students with low vision to use their available vision to the fullest, encourage print reading over braille, ensure appropriate placement, and promote timely adoption and proper usage of optical device.

Introduction: High altitude, often characterized by settings over 2400m, can be detrimental to the human body and pose a significant risk to ocular health. Reports concerning various ocular morbidities occurring as a consequence of high altitude are limited in the current literature. Objectives: This study was aimed at evaluating the ocular health of porters working at high altitudesof Himalayas in Nepal. Materials and methods: A mobile eye clinic was set up in Ghat and patient data were collected from its out-patient unit by a team of seven optometrists which was run for five days. Ghat is a small village in north-eastern Nepal, located at 2860 m altitude. Travellers walking through the trekking route were invited to get their eyes checked at the clinic. Comprehensive ocular examinations were performed, including visual acuities, objective and subjective refraction, anterior and posterior segment evaluations, and intraocular pressure measurements; blood pressure and blood glucose levels were also measured as required. Ocular therapeutics, prescription glasses, sunglasses and ocular health referrals were provided free of cost as necessary. A total of 1890 people visited the eye clinic, among which 57.4% (n=1084) were porters. Conclusions: Almost half of the porters had an ocular morbidity. Correctable refractive error was most prevalent, with other ocular health-related complications, including dry eye disease, infectious disorders, glaucoma and cataract. Proper provision of regular and effective eye care services should be made more available for those residing at these high altitudes in Nepal.

Introduction: Preventable and treatable eye diseases are still major causes of blindness in rural communities.

With high sensitivity and specificity values, vision screening done by trained students is effective for screening visual acuity of school children. Countries with limited eye-care professionals and infrastructures can effectively train and utilize students for timely detection of poor vision among children.

In this rare case, the distinct features of retinitis pigmentosa are seen only in one eye, and this can be further confirmed from multifocal ERG and visual field.

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This thesis investigates the visual processes mediated via the fifth and most sparsely represented photoreceptor class in the human eye; melanopsin ganglion cells. It was determined that melanopsin-directed lighting increases the contrast sensitivity of the canonical cone pathway to enhance the perception of brightness. The melanopsin pathway also transmits visual information independently of rod and cone mediated vision. During decision making, its activation produces a signature biphasic pupil dilation. These outcomes inform the development of new energy-efficient lighting spectrums designed to modulate the effects of light on mood and cognition mediated via the melanopsin pathway.