One million Americans were estimated to be legally blind.

An individual who cannot see 20/200 or better is considered legally blind. Even though it is just a legal definition, it means that a lot of people can have vision loss and see more than what people believe they should be able to see or they can have vision loss and see less than what people believe they should see.

For government services as well as other legal measures like driving, we have to have a notation of measurements. This is why the term legal blindness is used. 20/200 is a standard, but there are other factors involved, including visual field, since in some circumstances you can see 20/20, but your visual field prevents you from seeing clearly. All of those things are important when it comes to vision. Nevertheless, the term legal blindness is just a term to delineate legality in vision.

The U.S. government’s definition is as follows:

• If you cannot reach better than 20/200 with corrective measures in the best eye
• If you have 20 degrees or less of your field of vision

What conditions cause legal blindness?

Causes of blindness include:

• People who are born blind may have visual deficiencies that meet this criteria.
• Numerous eye diseases and disorders can affect the optic nerve, including glaucoma, cataracts, diabetic retinopathy, stargardt disease, retinitis pigmentosa, ocular albinism, age-related macular degeneration, and other ocular disorders.
• Trauma can cause vision deficits which fall under this legal standard.