Causes of visual impairment – According to the American Foundation for the Blind, 10 million people in the US have some form of visual impairment.  According to some sources, one million people over 40 are blind and 2.4 million have trouble seeing.

The number of adults who have trouble seeing or who are considered visually impaired is likely to double over the next few decades as the number of older people grows.

The numbers also show that only 46% of adults of working age have vision problems and that only 32% of legally blind adults of working age have jobs.  A term used for any kind of vision loss is “visual impairment.” This includes people who can barely see or who have lost some of their sight.

Some people lose their visual sharpness, which means they can’t see things as clearly as they used to. For some people, it may also be due to a loss of visual field, which means they can’t see as far to the sides without moving their eyes or head.

There are several ways to explain how bad someone’s vision loss is. The World Health Organization says that someone has “low vision” if their best-corrected vision is between 20/70 and 20/400 or if they can only see 20 degrees or less. As long as the best correction (ie. Glasses) is used, “blindness” means having a vision field of 10 degrees or less or more than 20/400.

Causes for Visual Impairment

Common causes of visual impairment including blindness:

• Injuries
• Amblyopia
• Infections  of the eyes
• refractive errors
• cataract
• diabetic retinopathy
• glaucoma
• age-related macular degeneration

The reasons for vision loss are very different between and within countries, depending on how easy it is to get eye care, how much it costs, and how educated the people are. For instance, more people in low- and middle-income countries have trouble seeing because of cataracts that haven’t been operated on. Diseases like cataracts and age-related retinal degeneration are more common in places with high incomes.

In low-income countries, hereditary blindness is the most common cause of vision loss in children. In middle-income countries, retinopathy of prematurity is more common.

Uncorrected refractive error is still the most common reason why children and adults have visual impairments in every country.

Amblyopia

If a child doesn’t use one eye enough when they are young, they may develop amblyopia, which means they can’t see as well out of that eye. This is one of the common causes of visual impairment in childhood There are times when a child’s eyes send different signals to the brain. For example, one eye may focus better than the other. That’s when the brain might block or turn off images from the weaker eye, which stops that eye from growing properly. It’s also called a “lazy eye.” A common cause of amblyopia is strabismus, which means crossed or misaligned eyes. This is because the brain will suppress images sent by one of the crooked eyes.

Causes of cortical visual impairment

Cortical visual impairment (CVI) is a brain condition that makes it hard to see certain things, like people, school materials, and the surroundings. Students with these behavioral and visual traits are thought to have CVI if they have a loss of vision or if their performance shows that they are visually disabled.

Retinopathy of prematurity

Some kids who were born early get this problem in their retinas. They get blood vessels that grow into parts of their retina that they don’t belong. Scar tissue can form in their eye and hurt them, which can cause them to lose a lot of vision or even go blind.

Optic Nerve Hypoplasia

The optic nerves don’t grow properly, (they are small) which is called optic nerve hypoplasia (ONH). This is a birth defect.  It is not genetic, ONH does not get worse over time, and it cannot be fixed. One of the three most common reasons kids lose their sight is ONH.

Albinism

Albinism means that a person’s eyes, skin, or hair don’t have any color or have very little. One of their genes doesn’t make as much melanin as it should, which is an important pigment for the eye to fully grow. Lack of melanin during growth of the retina is the main reason why people with albinism have trouble seeing.

Infections of the eyes

If the mother has a virus like German measles, that virus can be passed to the growing child during pregnancy. If this happens, the baby may be born blind or with vision problems.

There is a bacteria called Chlamydia trachomatis that can cause trachoma in the eyes. This may adversely impact your eyesight. This is seen in emerging and underdeveloped countries that don’t have good drainage or water systems.  The most common infectious cause of blindness in the world is trachoma. Chronic keratoconjunctivitis is caused by the obligate intracellular bug Chlamydia trachomatis in this disease. 

Trachomatis can be passed on by touching an infected person’s eyes or nose or by touching clothes or flies that have been in contact with an infected person’s eyes or nose. Trachoma can also spread more easily in places with bad drainage, lots of people living together, and not enough clean water and toilets. The main people who spread diseases are children and the women who care for them.

Cataracts

Cataracts make it hard to see because they cloud the lenses of your eyes, making things less clear and yellowed. If you can’t get surgery for your severe cataracts, you could go blind.

Diabetic retinopathy

Diabetic retinopathy is an eye problem that can happen if you have diabetes. The light-sensitive tissue at the back of the eye (retina) has blood vessel damage that leads to it.

Diabetic retinopathy may not show any signs at first, or it may only cause mild eye problems. But it can make the visually impaired or even blind.

People with either type 1 or type 2 diabetes can get this problem. You are more likely to get this eye problem if you have diabetes for a long time and don’t keep your blood sugar under control.

Glaucoma

Damage to the optic nerve in the back of the eye can lead to glaucoma, a group of eye diseases that can make you lose your peripheral vision.  

Sometimes the signs come on so slowly that you might not even notice them. A full dilated eye test is the only way to know for sure if you have glaucoma.  

Early diagnosis and treatment can often stop the damage and keep your eyes safe.  

Types of Glaucoma

People in the US usually mean “open-angle glaucoma,” which is the most common type of glaucoma. Angle-closure glaucoma and congenital glaucoma are two other types that happen less often.

Age Related Macular Degeneration

Over time, the macula, which is the most sensitive part of the eye, slowly starts to break down. This is called macular degeneration. The disease causes a gradual loss of central vision, which is the ability to see small things right in front of you. Most of the time, macular degeneration happens to older people (especially those over 60), but it can also happen to younger people. Age-related macular degeneration is more likely to happen if you spend too much time in the sun or smoke. Reading or watching TV may become harder, or your vision may become blurry, making straight lines look wavy or things look bigger or smaller than they are.

Leber hereditary optic neuropathy

Vision loss that is passed down through families is called Leber hereditary optic neuropathy (LHON). People with this disease usually start showing symptoms in their teens or twenties, but sometimes they can start showing symptoms in early childhood or later in adulthood. Men suffer damage a lot more often than women, but no one knows why.

Vision blurring and cloudiness are often the first signs of LHON. These vision issues can start in one eye or both eyes at the same time. If vision loss starts in one eye, it usually spreads to the other eye within a few weeks or months. Over time, both eyes’ vision gets worse, and people lose a lot of their color and sharpness of vision. The main part of vision that this condition affects is central vision, which is needed for detailed jobs like reading, driving, and recognizing people. Cells die in the optic nerve, which sends visual information from the eyes to the brain. This leads to vision loss. Some people’s center vision gets better over time, but for most people, the vision loss is severe and will not go away.

Living with visual impairment

People who lose some or all of their sight do lose the ability to do some everyday things, like drive a car, but a lot of them are still able to live fully independent lives. They still have families, go to work every day, and do different kinds of fun things.

People who are blind or have low vision can make many daily changes that will make their lives better. Some tools can help them see better, for example, if they still have some vision. There are lots of different kinds of magnifiers that can be used in various ways. There are magnifiers and binoculars that can be attached to glasses and put on them directly. These are useful because they let the person use their hands for other things.

To see things up close, you use a magnifier. To see things far away, like a ball game, you use a telescope. There are also handheld and desk magnifiers that can be used while you’re on the go. People can read things like price tags, restaurant menus, and recipes better with hand-held magnifiers. The smaller one, on the other hand, is great for doing hobbies or reading the newspaper at home.

As technology has improved, it has opened up a lot of exciting possibilities for blind or visually disabled people. These opportunities can help someone get and keep a job. People who are blind or have poor vision can easily use many computer programs with the help of text-to-speech tools and screen magnification. Screen readers use a voice synthesizer to read what’s on the screen and help the user. VoiceOver for Apple devices and Thunder for Windows users are two examples. Some apps, like JAWS, can turn the words on the screen into braille so that the person can read them. The majority of people can usually use a computer and complete most current office tasks by using a mix of these tools.

FAQ’s of causes of visual impairment

How does not being able to see affect daily life?

Losing your sight can have a big effect on both your mental and physical health. It can make you more likely to fall, which can lower your quality of life. People who lose their sight are more likely to be lonely, cut off from other people, and feel worried, scared, or anxious. People who have lost their sight often feel depressed.

Is not being able to see a disability?

You may still be able to get disability benefits even if your vision doesn’t meet the standard definition of blindness. This is true if your eye problems keep you from working, either by themselves or with other health problems. You must have worked long enough and paid enough Social Security taxes to get SSDI payments.

What effects does not being able to see have on your daily life?

In short. If someone loses their sight, they might stop going out with other people and end up being alone and separated. People who are blind or have low vision can make most social events, like vacations and trips, work for them. Most of the time, people who can see are needed to help.