Low vision is the leading cause of disability in the United States. A low vision exam helps your doctor find ways to enhance your usable sight and improve your quality of life.
What Is Low Vision?
Low vision is vision loss that can’t be corrected even with glasses, contacts, medication, or surgery. You might have some vision, but it’s hard to do everyday activities like reading, driving, or household chores. It’s more than needing glasses and can cause disability.
Your doctor measures the clarity or sharpness of your vision, called visual acuity, by how well you see at a distance of 20 feet. If you have 20/20 vision, you have normal vision, which means you can see clearly from 20 feet away. If you have 20/70 vision, it means you must be as close as 20 feet to see what people with normal vision can see 70 feet away.
For most people, glasses or medical treatment can correct these visual impairments. Low vision happens when your glasses-corrected vision in your best eye still measures as 20/70 or worse.
Types of Low Vision
Low vision is usually described by your visual acuity, but the definition recently changed to include loss of your visual field. This is the portion of space you can see without moving your eyes.
There are different types of low vision, and these can vary depending on the eye condition you have. These include:
- Peripheral vision loss, where you can’t see from the corners of your eyes
- Central vision loss, where you can’t see from the center of your vision
- Night blindness, where you can’t see in low light
- Glare sensitivity, where you are extremely sensitive to normal volumes of light
- Contrast sensitivity, where your eyesight is hazy or cloudy
- Blurry vision
In a medical setting, your doctor might use the term low vision or the term blindness for severe or total vision loss. If you have low vision that’s 20/200 or worse, even with correction, you may qualify as legally blind. The US government uses this term to define eligibility for disability benefits, low vision devices, training, rehabilitation, and tax programs.
What Is a Low Vision Exam?
A low vision test is not the same as your typical eye check-up. It’s a longer, more in-depth exam where your doctor reviews your glasses prescription and checks your current vision abilities. The exam helps them learn about your vision goals and find tools to help you live independently.
There are several parts to a low vision exam.
Health history. Your eye doctor might start the appointment by taking your general health history. They’ll ask about other conditions you have, medications you take, and your family medical history. They might ask questions about habits that can affect your health, like smoking. They may discuss your mental health to see how you’re coping with your vision loss.
Vision history. Your doctor will also ask about your symptoms and about any eye conditions you currently have or have had in the past.
Vision tests. Next, they’ll do several exams to check your eyesight and identify your remaining vision. Your doctor might do tests on high-tech machines or simple charts. These often include:
- Visual acuity tests, where you read lines on a low vision eye chart
- Visual field tests, which check for central or peripheral vision loss
- Amsler grid test, where you look at a grid chart and check for wavy lines
- Depth perception tests
- Color vision tests
Eye exam. Your doctor will examine your eyes, including your eye fluid pressure, tear film, pupil shape and response to light, and muscles. They might take pictures of your eye, too.
Prescription review. Once these tests are complete, your doctor will closely review your glasses prescription. They’ll make sure the prescription you have is the best one for your eyes.
Functional eye exam. Then they’ll ask you about your vision to determine how it affects your daily life. These questions can vary, but they’ll ask about the size of print you can read, whether you can see to pay your bills, or if you can read your watch.
Your doctor might also ask about your personal care activities: whether you can do the laundry, shave independently, travel on your own, or whether your low vision has affected your job. Once they have this information, they’ll ask you about your goals and what skills you want to do independently.
What Are Low Vision Treatments?
There is no cure for low vision. It is a chronic visual impairment, but sometimes medicine, glasses, and other tools can help or make your life easier.
The results of your low vision exam help your doctor build a detailed treatment plan to maximize your usable eyesight. They’ll suggest the best types of low vision assistance that are best for your goals and needs.
Low vision rehab. People with low vision benefit from rehabilitative care. Therapists can help you learn new skills and ways to adapt to low vision. These can include orientation and mobility training to help you get around safely, making your house more accessible, lighting changes, and technology training.
Low vision aids. Vision devices are prescription tools that help you see better. There are lots of different types, including:
- Magnifiers, either handheld or mounted to your glasses
- Telescopes for long-distance sight, which can be handheld or mounted to your glasses
- Digital handheld magnifiers, which magnify objects on a digital screen where you can adjust the brightness and contrast
- Video magnifiers, which are portable or mounted to a table and bigger than a digital magnifier
- Large-print books and newspapers
Assistive technology. There are lots of electronic devices and apps that help people with low vision. These range from audiobooks and screen readers to sensing devices and text-to-speech technology.
You might need to use one or a few tools, but even a slight change in your vision from these aids can make a big difference in your daily life.
Bottom Line
There’s no way to regain vision loss, but you can adapt to your low vision and live a full life. A low vision exam can help you get training and tools that improve your abilities and your everyday life.