Legally Blind: Definition
Surprisingly enough, the parameters for legal blindness are set by the government, not your eye doctor.
This term refers to someone who is deemed unable to see at a certain level. Most health institutions and government agencies agree that if the vision in your best eye is 20/200 with correction, then you are legally blind.
To put this into perspective, let's compare to somebody with normal vision is 20/20:
If your eyesight is 20/20, you can clearly see an object that is 20 feet away from you. Similarly, the average person at this level can see 140 degrees without turning their head.
When someone is legally blind with a vision of 20/200, their field of vision is less than 20 degrees.
In other words, a person who is legally blind can see an object from 20 feet away that a person with normal vision could see from 200 feet away.
As you can imagine, this would make activities like driving and holding certain types of employment very difficult.
The definition for legal blindness is used as the guideline to allow these individuals to receive government assistance like Social Security disability benefits. Likewise, the Department of motor vehicles set this prescription as the line where it is no longer safe for you to drive.
It is important to know that the prescription for total blindness is 20/200, but that is after your eyesight has been corrected. That means if your natural eyes see at 20/200, but you can improve it to 80/200 with glasses or contacts, then you are not legally blind.
How Does it Compare to Total Blindness?
The conditions for legal blindness and complete blindness are very different.
Someone who is completely blind cannot see any light or shapes in front of them. They can see nothing at all, which includes colors, shapes, or light.
Individuals who are legally blind may still be able to see - the issue is that the image is not very clear. They can still see colors, shapes, lights, and shadows, but they will struggle to see things from far away and require assistance with driving.
What is Considered Legally Blind?
Just because you cannot see more than a foot or two in front of you with your natural eyesight does not mean that you are legally blind. If you can use glasses or contacts to correct your vision above 20/200, you do not qualify to be labeled legally blind.
With that being said, over 1,000,000 Americans are legally blind. Many of them suffer from conditions like cataracts, diabetes, glaucoma, or macular degeneration that affect their eyes to the point where they can no longer see.
Cataracts refer to the clouding of the lens in your eye. This causes blurry vision and can result in you becoming legally blind. Most cataracts develop as you age and your lens deteriorates, but genetic disorders and diabetes can speed up this process.
Glaucoma is a condition where there is increased pressure within your eye. As the pressure builds up, it can eventually damage your optic nerve, which will decrease your ability to see.
Age-related macular degeneration, or AMD, is the leading cause of poor vision and people over 60. This disease causes the central part of your retina, known as the macula, to deteriorate. The macula is responsible for producing sharp, clear images that let you do things like reading and driving.
If you feel like your vision - even with correction - prevents you from driving or working safely, you must see an eye doctor to determine whether or not you are legally blind.