OPHTHALMIC CAUSES
- Refractive error
- Cataract
- Diabetic retinopathy
- Macular degeneration
- Glaucoma
- Corneal opacity
- Pterygium
- Chronic uveitis
SYSTEMIC CAUSES
- Pituitary tumor (bitemporal hemianopsia)
- Cerebrovascular disease or brain tumor
- Intraorbital tumor
- Toxic optic neuropathy (e.g. methanol)
- Marfan syndrome or homocystinuria leading to lens dislocation
- Infection (trachoma, leprosy, onchocerciacsis)
- Vitamin A deficiency