Legally Blind – Definition, Causes, Eligibility, Treatments
Blindness is the loss of vision in a way that tools such as glasses and contact lenses cannot fix. It is also the complete absence of vision. Blindness is often a diagnosis that you get from an ophthalmologist.
Legally blind, on the other hand, is a diagnosis you technically get from the U.S government. This term describes a person with vision below a specific measurement. It is not the same as total blindness. The government and health insurers use the term to determine eligibility for certain benefits.
What Causes Legal Blindness?
Legal blindness has many causes. Some of the diseases that can cause legal blindness include:
- Age-Related Macular Degeneration (AMD). This disease affects the normal central part of the retina. Patients get severely damaged macula in both eyes. Their peripheral vision remains intact so they can see shapes and movements.
- Cataracts. Severe cataracts can cause legal blindness. They prevent enough light from reaching the lens. This causes cloudy eyes, so you can see but not clearly.
- Diabetic Retinopathy. This is a retinal disease that can cause legal blindness. It is a complication of diabetes where your retina swells or bleeds. It can also occur as retinal detachment.
- Retinitis Pigmentosa. This rare genetic disease affects the retina and can cause legal blindness. This condition can cause what is known as ‘tunnel vision’ where only a tiny window of central vision remains. This small field of vision, or lack of peripheral vision, is considered legally blind.
These diseases are more likely to occur in older people. Therefore, most of the people who are legally blind are over the age of 40. Luckily you can prevent vision loss and even treat some of the diseases that cause it.
What Qualifies As Legal Blindness?
Normal vision is 20/20. This term means that you can see an object clearly, while it is 20 feet away. If you are legally blind, your vision is 20/200 or less in your best-performing eye. It could also mean that your field of vision is less than 20 degrees.
20/200 means that if an object is 200 feet away, you have to stand 20 feet from it so you can see it clearly. In comparison, a person with great vision can stand 200 feet away and see the object perfectly.
Legal Blindness Test
An eye doctor measures visual acuity to determine if you are legally blind. Visual acuity is the clarity of a person’s vision. The most common test for visual acuity is the Snellen eye chart. The chat has several lines of letters. The letters on the first line are the largest, and they get smaller with each line.
Anyone who is legally blind would only be able to read the top line of the chart with the help of corrective lenses. The line below is for people with 20/100 vision. Anyone who cannot view this line but sees somewhere between 20/100 and 20/200 is still legally blind.
Doctors can also conduct a confrontational visual field test. The eye doctor will have you cover one eye at a time then hold up one or more fingers in different positions. These positions are in different quadrants of the visual field. The doctor will examine if you can see the finger while keeping your eyes focused on a central point in front of you. If you cannot, then you are diagnosed with legal blindness.
Doctors can also conduct modern and comprehensive tests to determine legal blindness. These computerized tests use flickering, flashing, or moving lights and images to measure your visual field. Patients often have to press a button if they see any lights or images. Failing to meet the minimum button presses means that you are legally blind.
Treatments for Legal Blindness
Treating legal blindness depends on what caused it in the first place. Therefore, you can treat some of the causes of legal blindness. For others, you can only manage the symptoms. Treatment options for legal blindness include:
- For Age-Related Macular Degeneration (AMD), patients can receive regular injections to slow or stop vision loss. However, this is only an option for patients with wet AMD. Patients with dry AMD are not so lucky. Patients can also adopt a healthier diet consisting of salmon, vegetables, fruits, and sardines. Quitting smoking can also help, plus taking supplements.
- For Retinitis Pigmentosa, patients can get retina gene therapy. It is a newly FDA-approved treatment that works by injecting normal copies of the RPE65 gene into the retinas of patients born with mutations in this gene. Further studies are ongoing, but it is a promising treatment so far.
- For Diabetic Retinopathy, patients can prevent worsening of the condition with injections, eye surgery, and laser treatments. It is important to note that you cannot reverse the effects of the disease, but you can prevent it from getting worse. Patients can also learn to control blood sugar levels to protect themselves more.
- For Glaucoma, patients can get medication to lower intraocular pressure. Laser treatments and surgery are also options. However, these treatments only prevent further damage as you cannot reverse the existing damage from glaucoma.
- For Cataracts, patients will require surgery to improve the condition. Luckily, doctors can surgically remove the lens with cataracts and replace it with an artificial one. It enhances vision significantly.
What Is It Like To Be Legally Blind?
Legal blindness varies from person to person. Some people can see objects at a distance but not from the sides. Others have trouble seeing things that are far away.
Because of the risk, anyone legally blind is not allowed to drive or operate other heavy machinery. It also means that you may struggle at competitive sports activities. However, you can still live a fulfilling life.
There are programs for counseling and interacting with people who have the same condition. Through these programs, you can find fun activities you can still do.
Additionally, being legally blind makes you eligible for certain benefits through the Social Security Administration (SSA). These benefits make your life better by ensuring that you remain active in your daily life.