What Does It Mean to Be Legally Blind?


Most of us know that when someone is blind, they don’t see anything at all. However, many people do not know that you can be “legally blind” and still have sight. So, let’s examine what it means to be legally blind and the many helpful resources available if you are.

Legally Blind Definition

The term legally blind comes from the government, not your eye doctor. Government agencies use this term to determine eligibility for certain disability benefits, tax exemptions, and low vision training.

Two tests determine if you can be considered legally blind, a visual acuity test and a visual field test.

Testing Your Visual Acuity

boy getting visual acuity test

The phrase 20/20 is used to express normal visual acuity or the clarity or sharpness of your vision, measured at a distance of 20 feet. If your visual acuity is 20/200 or worse even with your glasses prescription, you would be considered legally blind.

When you are legally blind, your best-corrected vision is 20/200, meaning you can read at 20 feet away what a person with normal vision can see from 200 feet away.

Testing Peripheral Vision

If you have trouble seeing images to the sides or even up or down without moving your head, you are considered to have a field of vision impairment.

driver wearing glasses leaning out of window with shocked expression

For example, you might be able to read the smallest row of letters on an eye chart but can’t see the person standing next to you without turning your head. This describes legal blindness due to poor peripheral vision.

Peripheral vision has two components: lateral, side to side vision measured at 180 degrees and vertical, up and down vision measured at 135 degrees.

woman taking a visual field test with a perimeter
Taking a visual field test

To determine if you have an issue with your peripheral vision, you will take a visual field test.

Your eye doctor uses a machine called a perimeter to perform your visual field test.

Visual field tests can determine if you have a normal field of view without any blind spots or unusual narrowing of your peripheral vision.

You are considered legally blind if testing determines a visual field of 20 degrees or less. You may hear this referred to as tunnel vision.

What Does 20/20 Vision Mean?

Age-related macular degeneration – A small portion of the retina (macula) deteriorates over time and gradually leads to central vision loss. As a result, you lose central vision but retain peripheral vision.

Cataracts – A cataract is a clouding of the usually clear lens of the eye. Clouded vision caused by cataracts can make reading and driving a car difficult, especially at night.

Diabetic retinopathy – Retinal damage caused by diabetes, particularly in cases where diabetes is poorly managed.

Glaucoma – This condition occurs when high fluid pressure inside the eye damages the retina.

According to webmd.com, an estimated 1.1 million Americans are legally blind.

Frequently Asked Questions (FAQs)

How do I know if I am legally blind?

A strong prescription does not mean you are legally blind if your vision can be improved to better than 20/200 while wearing your glasses or contacts. However, if you still have 20/200 eyesight or worse, even with vision correction, you are considered legally blind.

What prescription is legally blind?

If your prescription is -2.50 or worse and cannot be corrected with a prescription, you would be considered legally blind.

My doctor told me I have a cataract. Can I receive government benefits?

Most governments will pay benefits only if you have 20/200 vision that cannot be corrected with prescription glasses or contact lenses. There are many rules involved with receiving benefits. It is best to contact your government’s social services agency for clarification.

My visual acuity is 20/400 without glasses; however, I see 20/20 with my glasses on. Am I legally blind?

No. You are only considered legally blind if your vision can not be corrected better than 20/200.

Many resources are available to assist you if you are legally blind.

Low Vision and Technology

Iris Vision manufactures low vision assistive devices that use technology to aid the visually impaired lead a better life.

There are many apps designed for blind or low-vision individuals. So whether you use an Apple or Android device, they go with you wherever you go.

Therapy and Rehabilitation Services

There are vision rehabilitation services designed to help you cope with the challenges that come with the loss of vision. Vision rehab therapists specialize in coaching people to live independently and maintain a good quality of life.

Occupational therapy assists the visually impaired to continue to do things that are important to them in daily life, such as cooking, shopping, or taking the correct medication. Occupational therapy practitioners use the term occupation to represent these activities.

occupational therapist assisting legally blind man

Counseling and Psychological Services are available for individuals who want to discuss any of the challenges they face due to their vision loss.