The term legally blind is not used by optometrists or ophthalmologists as a diagnosis. Instead, we diagnose patients using terms like “normal, low vision, or impaired vision,” depending on their visual acuity. However, the U.S. government uses the term “legally blind” as a qualifier to support those with low vision that affects daily activities.
If the use of corrective lenses doesn’t improve vision enough to function safely through your daily routine, (driving, walking, reading grocery store labels, etc.) or compromises your ability to navigate the academic or job arena, the “legally blind” qualifier enables you to receive free or very low-cost support to lead a normal life.
Legally Blind: What Does It Mean & Is It Correctable?
When you visit your optometrist and go through an eye exam, they use the Snellen Eye Chart to discover what you can see without glasses and determine your prescription. The point is to assess what you can see at 20 feet away. Normal or “perfect” vision is 20/20. This means you can see exactly what you’re supposed to at 20-feet. If your vision is 20/30, it means that what a normal person can see at 30 feet, you can’t see until you’re 20 feet away.
Impaired vision vs. legally blind
The higher the distance on the bottom becomes, the worse your vision is, but you are still considered to be in the normal to low-normal range until visual acuity reaches 20/70 – even with eyeglasses or contacts.
Visually impaired (low vision)
At that point, patients are considered “visually impaired.” Your optometrist may also use the term “low vision,” to describe your visual acuity. If this is the case, we’ll start using different types of tests and screening tools to assess what you can and can’t see to personalize treatment.
Some level of reduced visual acuity is normal as we age, but most of the time, this is corrected with the right lens prescription or some type of surgery, such as LASIK or cataract surgery. Then there is a smaller percentage of the population for whom traditional lens prescriptions don’t work. Here is an age-related breakdown from the NIH of the percentage of the population considered visually impaired (20/70 or worse):
Age (years) Percent of people with visual impairment that
CANNOT be corrected with glasses/contact lenses
12-19 years 6.9%
20-39 years 10.0%
40-59 years 5.6%
60+ years 41.5%
As you can see, the older you are, the more likely visual acuity is to move into the visually impaired category. While age and genetics play a role. So does your lifestyle. A large amount of age-related visual impairment correlates to health conditions affecting eye health and vision, such as diabetes and heart disease.
Of the 14 million individuals with impaired vision, about one million of them meet the criteria for legal blindness. Unless you have cataracts and qualify for surgical correction, odds are there is no way to reverse vision loss for legally blind individuals.
According to the American Foundation for the Blind (AFB):
“Legal blindness” is a definition used by the United States government to determine eligibility for vocational training, rehabilitation, schooling, disability benefits, low vision devices, and tax exemption programs. It’s not a functional low vision definition and doesn’t tell us very much at all about what a person can and cannot see.
Part 1 of the U.S. definition of legal blindness states this about visual acuity:
- A visual acuity of 20/200 or less in the better-seeing eye with best conventional correction (meaning with regular glasses or contact lenses).
Part 2 of the U.S. definition of legal blindness states this about visual field:
- OR a visual field (the total area an individual can see without moving the eyes from side to side) of 20 degrees or less (also called tunnel vision) in the better-seeing eye.
Most Common Causes of Legal Blindness
The most common causes of legal blindness are:
- Age-related macular degeneration
- Diabetic retinopathy
We want to reiterate that diet and lifestyle play a significant role in the development and progression of all of these common causes of blindness. Maintaining a healthy diet is one of the best things you can do to slow down the progression of visual impairment and prevent going blind.
FAQ’s About Legal Blindness
Here are some of the questions patients have about going blind or what it’s like to be blind:
What can you see (or not see) if you’re blind?
This question depends on the type of vision loss you have. For some, there is a general all-around blurriness. If someone is completely blind, things may be completely black (called “total blindness with NLP – no light perception), while others have some ability to tell changes in light.
However, some patients can only see through tunnel vision, and the surrounding area (peripheral vision) is black. This is common for those with glaucoma or retinitis pigmentosa. Others may have vision that’s obscured with various blind spots throughout the field of vision, often affecting those with diabetes or optic nerve inflammation. There are also variations in blindness depending on certain conditions, such as insufficient lighting, glare, a person’s level of fatigue, etc.
Can you reverse blindness?
Corrective lenses are the first line of defense against vision loss. Surgery may be an option when astigmatism or cataracts cause vision impairment. However, you may not be a candidate for LASIK surgery if vision loss is past a certain point or certain health issues are present.
What support is available to the legally blind?
Many of our patients are relieved when they cross over to the legally blind point because the difference between someone with 20/190 and 20/200 isn’t all that different. Still, the benefits and support tools available for someone with a legally blind diagnosis make life much easier. These include things like:
- Potential disability status through social security
- Rehabilitation and OT
- Guide dog
- Equipment to support daily life such as free audiobook/textbook options, magnifying readers, gadgets specifically designed for the visually impaired, special lamps, alarm clocks, etc.
- Career support
- Advocacy and support for students in the classroom
If you are legally blind, the staff at Atlantic Eye Institute provides a list of resources and will do all we can to collaborate with others to get the support you need.
Schedule Special Low Vision Eye Exams At Atlantic Eye Institute
Do you have a low or impaired vision diagnosis? Then, schedule your next low vision eye exam with us here at Atlantic Eye Institute. Our amazing team of optometrists and ophthalmologists work closely together to ensure you receive the highest-quality vision care and support tools available.