Can you tell me what the leading cause of loss of vision is?

Good question: It depends on the type of vision loss you mean. The leading cause of reversible blindness worldwide is cataract, while the leading cause of permanent vision loss in the United States is glaucoma. Leading causes of blurred vision include nearightedness and farsightedness.

Depends on group: For people over 65 age related macular degeneration leads. For younger people diabetic retinopathy is the cause. Outside the us infectious causes like trachoma blind people at high rates.

Cataracts, worldwide: According to lighthouse for the blind, nearly 50% of vission loss worldwide is still cataracts, a treatable cause. Next is glaucoma, which is also treatable if caught early.