Table 6 Types of visual impairments in India

Ocular albinism

Pinkish/light iris, photophobia, nystagmus, strabismus, reduced depth perception, mild to moderate central vision loss [14]

Rare (< 1% of total visual impairments)

Genetic disorder causing melanin deficiency

Vision loss present at birth does not worsen; associated with poor binocular vision and head tilt

Retinitis pigmentosa

Reduced vision, narrowing field of vision, night blindness, glare sensitivity, difficulty with peripheral vision, impacts mobility, driving, and close tasks [15]

1 in 3,000 (approximately 0.03% of the population)

Hereditary retinal degeneration

Symptoms typically manifest between ages 10 and 30. Progresses to severe vision loss or blindness over time

Cataracts

Glare sensitivity, blurred vision, halos around lights, double vision, faded colors,"veil"effect on vision [16]

62.6% of blindness cases in India

Aging, eye trauma, congenital factors

Primary cause of avoidable blindness globally and in India. Commonly treatable through surgery

Diabetic retinopathy

Fluctuating vision, blurred/distorted vision, patchy vision loss, increased light sensitivity, glare [17]

16.9% of adults with diabetes have retinopathy

Diabetes complications damaging retinal blood vessels

Early stages often asymptomatic; risk increases with poor diabetes management

Glaucoma

Gradual loss of peripheral vision (tunnel vision), blurred vision, difficulty in low light, night blindness, glare sensitivity [18]

12% of blindness cases in India

Increased intraocular pressure damaging optic nerves, poor drainage of eye fluid

Two main types: open-angle and closed-angle. Often painless, making early detection challenging

Age-related macular degeneration (AMD)

Central vision distortion, difficulty reading, recognizing faces, and seeing objects clearly [19]

2.7% prevalence among individuals aged 50 + 

Degeneration of the macula, linked to aging

Early diagnosis and management can slow progression; affects central vision critical for tasks like reading and driving

Stargardt disease

Loss of central vision, gray/black spots in vision, light sensitivity, difficulty adjusting between light and dark, color blindness [20]

1 in 8,000 to 10,000 globally

Inherited juvenile macular degeneration

Typically manifests in adolescence; gradual but progressive loss of central vision

Nystagmus

Involuntary eye movements, blurred vision, head tilt to stabilize vision [21]

Rare (specific data not widely available)

Abnormal brain function controlling eye movements

Can occur at birth or develop later; head posture adjustments may alleviate vision issues but lead to musculoskeletal strain