Approximately 1.3 million Americans are considered legally blind. This costs the US government $4 billion USD per year. The rate of blindness is expected to increase over time due to increasing age of the population. By 2030, there will be an expected 2.4 million legally blind people in the US.What is Blindness?
Traditionally, blindness meant being totally sightless but there are different types of blindness that include color blindness or the ability to see light and shapes but with no definition. Only a small percentage of people who are blind actually see only darkness.
Low vision means that even with eyeglasses or surgery, your vision would be poor. Of the 300 million to 400 million people who are technically blind throughout the world, only about 50 million are completely blind. About 80 percent of cases of blindness occur in those greater than 50 years of age.
There are different types of blindness, including color blindness. In color blindness, certain colors cannot be distinguished from other colors. It is hereditary and affects about 1 percent of females and 8 percent of males. They usually have normal vision in all other ways.
Night blindness can be acquired or inherited. It involves poor vision under situations of low light. Most of these people function normally under normal light conditions. It does not generally involve sightlessness.
Snow blindness involves a temporary loss of vision that occurs when the eyes are over-exposed the UV radiation and the cornea swells. Shapes and movement are still able to be detected.
Central vision blindness means that the person has a normal or nee normal peripheral vision but has a black spot in the middle of their central vision.
Complete blindness is what they mean by seeing only black. This can come from trauma to the eye or due to hereditary reasons. The vision can be black or varying shades of gray. Shapes and movement usually cannot be detected.Causes of Blindness
While some cases of blindness occur from birth, most cases of blindness are acquired from diseases affecting older people. These include:
Risk Factors for Blindness
- Cataracts. This involves clouding of the eye’s lenses. It affects 22 million people and are the greatest cause of blindness throughout the world, where surgery to correct it is not always available. Cataracts will affect more than half of people over the age of 80. The symptoms of cataracts include faded colors, blurry vision, sun glare, poor night vision, and double vision. People can get better with stronger glasses and anti-glare sun glasses but surgery can cure cataracts. It makes sure that the old lenses is removed and replaced with the artificial lens. Staying out of the sun can prevent or delay cataracts.
- Glaucoma. Glaucoma involves increased pressure in the vitreous humor of the eye so that the optic nerve of the eye is damaged. There are usually no symptoms until the pressure gets really high. It is a problem affecting 2.3 million Americans and another 2 million have no idea they have the disease. It is a common cause of blindness in African Americans and Latinos. African Americans have 4 times the rate of blindness compared to whites. Glaucoma is 15 times more likely to cause serious blindness in blacks between the ages of 45 to 64 when compared to whites. No cure exists for glaucoma. Surgery or the use of eye drops can keep the blindness away.
- Research is working on some of the genetic basis of glaucoma.
- Trauma. Trauma to the eye can come in the form of blunt trauma to the eye or penetrating trauma. Blunt trauma can be from a motor vehicle accident, baseball bat or ball striking the eye, causing disruption of the globe. Fortunately trauma to the eye is usually unilateral. Penetrating trauma can come from a knife wound or something like a fish hook to the eye. These can disrupt the globe and can do damage to the retina or the optic nerve itself. These types of trauma can cut through the lens, distorting vision.
- Macular Degeneration. This is a disease of the eye that affects people who are older. It is one of the major losses of vision in those older than 60. It destroys the macula, which is the portion of the vision that determines the sharpness of vision. Reading is destroyed along with the ability to drive, do tasks, and watch television. It is a painless disease but it is permanent. The changes in vision are gradual. There are two types of macular degeneration, wet macular degeneration and dry macular degeneration. In wet macular degeneration, abnormal blood vessels begin to grow beneath the macula. In dry macular degeneration, the cells of the macula simply break down so that vision gradually blurs in the middle of the visual field. There is no cure for macular degeneration but laser surgery, certain drugs, and photodynamic therapy can slow the progression of the disease.
- Diabetic Retinopathy. Diabetes causes diabetic retinopathy. It affects the seeing part of the eye—the retina. Blood cells of the eye are damaged and new, abnormal blood cells grow and interrupt the vision. They leak fluid into the vitreous humor of the eye and cause scar tissue to build up that separates the retina from the back wall of the eye. Blindness is the end result. It is usually bilateral. Diabetic retinopathy is treated with surgery or laser treatment. If the blood sugar is in good control, treatment can definitely slow the progression of the disease.
There are several risk factors for blindness. Some are avoidable and others are unavoidable. They include:
Symptoms of Blindness
- Age. Diseases such as macular degeneration and glaucoma increase with age.
- Risk behaviors. Those who engage in high risk behaviors run an increased risk for sustaining an injury to the eye—blunt force trauma or penetrating trauma.
- Genetics. For macular degeneration, several genes have been found that are related to getting the disease.
- Smoking. There is a documentable link between macular degeneration and smoking history.
- Alcohol use. There is an increase of 47 percent in getting macular degeneration if you drink more than three alcoholic beverages per day.
- Vitamin A Malabsorption. Diseases like pancreas, liver or bariatric surgery that decrease your ability to absorb vitamin A, leading to night blindness.
Blindness has several symptoms that partly depend on the type of blindness you have. Blindness can mean total darkness, as is common among those who are blind from birth. Usually there is no pain or discomfort associated with congenital blindness.
Many people, however, have acquired blindness. They may see some light, shadows and the movement of shadows. This type of blindness might be associated with discomfort in the eyes, the sensation of a foreign body in the eye, or fluid discharge from the eye. If the cornea has become infected and has caused you blindness, the cornea will be white so that you cannot see the iris or colored part of the eye. You may be technically blind but have the perception of floaters in your eye, which are strands of scar tissue that build up in the vitreous humor of the eyeball itself.Diagnosis of Blindness
In cases of traumatic blindness, the eye will look damaged and a visual acuity test may not be performed until the eye has healed to its maximum capacity. Then the vision is checked with a Snellen eye chart, which uses letters of different sizes to see what the vision is. If the vision is too bad to use the Snellen eye chart, the examiner can ask the patient how many fingers he or she is holding up or ask the patient what he or she can see, such as shadows, movement, light, etc. Remember that blindness can be unilateral or bilateral so each eye needs to be examined separately.
The type of blindness should be a part of the diagnosis. This is where the history of the onset of the blindness is important. Visual loss that is sudden in onset is different from visual loss that has been gradual in nature.
If the person is color blind, a couple of tests may be done. There is a set of Ishihara plates that involve the recognition of a number or object within a set of similarly colored dots. Different kinds of color vision abnormalities can be done using these plates. Alternatively, the doctor can ask the patient to arrange chips or other objects according to their color. Those with color blindness will group red and green chips together or other combinations, depending on what kind of color blindness they have.
There are several kinds and causes of blindness that doctors must go out of their way to diagnose. If they fail to detect these problems, they only get worse and the blindness can become irreparable. These include glaucoma or increased pressure in the eye that damages the optic nerve and macula, age related macular degeneration, cataracts, which can be completely reversed through surgery, and diabetic retinopathy, which can’t be corrected after a period of time has passed. If caught early, the retinopathy can be treated.Treatment of Blindness
The treatment of blindness varies according to its cause. For example, in developing countries, blindness is due to refractive error. They can see lights and shapes but cannot read or see things that are small. Just checking their vision and providing them with glasses can take care of their blindness so they can function in their society.
Nutritional causes of blindness include vitamin A deficiency, which leads especially to night blindness. This can be reversed by replacing the vitamin.
People with cataracts often need surgery to remove the cloudy lens. It is replaced with an artificial lens that corrects the vision. Inflammatory or infectious blindness can be treated with antibiotic or steroid drops. Diabetic retinopathy is often treated with laser surgery that cauterizes the bad blood vessels and scar tissue that build up when the blood sugar is consistently too high. Sometimes a vitrectomy is done to replace the vitreous humor with normal fluid.
There have been amazing advances in the use of stem cells to cure blindness. In one case, two women were cured of blindness using stem cell transplant. The treatment appears to be completely safe and, after four months, the stem cells remained in the retina and improved vision in at least two cases. Patients were given stem cells that are manipulated so that they grow into retinal cells. A total of 50,000 retinal cells were injected into one eye. The improvement in vision was slight but noticeable. In the future, this may become a commonplace treatment for several kinds of blindness.Complications of Blindness
There are many complications of becoming blind, including depression and anxiety that come from not being able to see the world around you. The feeling can be extremely isolating to the blind person, who may feel nervous around connecting with people they can’t see. The individual often has to take classes to learn how to get around in the city and with things like stop lights and traffic. These classes can be calming to the blind person.
The complications of color blindness involve a difficulty in interpreting street signs. Red lights look exactly like green lights so, unless the person can detect changes in the lightness or darkness of the traffic light, the person will have trouble detecting the presence of a red light.
Complications of diabetic retinopathy, especially if left undiagnosed or untreated, are worsening blindness. The individual continues to build up abnormal blood vessels and scar tissue, which causes increasing pinpoint areas of blindness that coalesce. There can also be bleeding into the retina which blinds the person in the area of the bleeding.
In cataracts, if not diagnosed and treated, there is progressive scarring and whitening of the cornea so there is visual disfiguration of the eye and the inability to see much more than shadows and the presence of light.
Many cases of blindness, especially things like macular degeneration, the failure to recognize and treat these disorders leads to their progression and to the progression of blindness. For older people or people at high risk of eye diseases that cause blindness, the individual should have an eye doctor appointment at least every year to be screened for these complex eye diseases.
If you or a loved one has suffered blindness as a result of someone else's negligence and would like to discuss your legal options with an experienced Sacramento Personal Injury Attorney, contact us online or call us at 916.921.6400 to set up a FREE consultation.