A Validation Study of Mobile Technologies for Assessing Visual Acuity and Eye Health Among Older Adults in India

Non-communicable diseases (NCDs) are a large and increasingly costly problem for India. Recent research estimates that NCDs could cost the Indian economy US$6.2 trillion from 2012-2030 if left unaddressed. For some NCDs, new solutions will need to be developed for diagnosis and treatment, while, for others, the necessary interventions exist but are not readily available to all who need them. Visual impairment is one area of health in which limited access to diagnostic and treatment technologies jeopardizes the health and economic well-being of the population. This is particularly true in India, where the population is rapidly aging and, despite the presence of some high-quality medical facilities, there remains a large burden of unaddressed visual impairment.

Loss of visual acuity can negatively impact individual and household income by reducing productivity or hours worked among the visually impaired; it can also affect economic wellbeing via the need for caretakers. There are two key tests that determine visual acuity and measure vision loss:

1. Basic visual acuity (BVA), which is assessed using the naked eye or, when applicable, eyeglasses, and
2. Best-corrected visual acuity (BCVA), which uses refraction to determine eyeglass/contact lens prescription.

In addition, diagnosing vision-hindering eye conditions requires specific medications or surgical procedures. Diagnosis of glaucoma, cataracts, or diabetic retinopathy typically requires a physician to examine a patient's retinas, corneas, and/or pupils at close range using specialized equipment, in conjunction with the visual acuity tests described above.

BCVA tests typically require heavy, cumbersome, and expensive equipment such as phoropters (instruments that measure the refractive state of the eye). Likewise, eye diseases typically require the use of specialized equipment such as slit lamp microscopes, ophthalmoscopes, and tonometers.