Types of Blindness
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| Blindness |
Whenever we hear of blindness, or spot a blind person, the most immediate reaction is that of heartfelt sympathy. But just for a minute, what if we had to step into a blind person's shoes? How would we then view things around us? As frightening as it sounds, it can really get you thinking. For starters, a blind person never judges anyone on the basis of their looks, appearance, or the way they dress, which rules out one of the most popular pastimes of sighted beings. Their best friend and guide is a four-legged furry creature, who seriously, is the best companion humans can have, blind or not. Also, darkness is not a thing to be afraid of; in fact, you get to read in the dark, and you are spared of the depraved entertainment that comes in the form of television.
The reason behind focusing on the bright side of visual disability, a seemingly debilitating condition is that millions of people around the world suffer from varying degrees of blindness caused by equally different reasons. But for these people to accept and embrace their condition is nothing short of an inspiration for all the others who take their senses for granted.
Blindness affects people of all ages across the world, and it is classified into different types, with some countries having set legal definitions for complete blindness. Let us take a look at the types of blindness and low vision.
Complete Blindness
Complete blindness refers to total loss of vision. This means that such people have a visual acuity of 20/200 in their good eye. So, when a person with normal vision can see an object from a distance of 200 feet, a person with complete blindness can see it not beyond 20 feet. Complete blindness can be caused by several factors, and it affects people of all ages due to different reasons, ranging from diabetes to cataracts to birth defects.
Diabetic Retinopathy: Diabetes causes this type of blindness, and adults as well as children are susceptible to it. In such cases, the blood vessels present in the back of the eye burst due to diabetes-related complications. This results in impaired vision, and is quite common among those who have suffered from diabetes for more than 10 years. Unfortunately, diabetic retinopathy does not usually show early signals. But it is often seen that these patients can gain a lot of help from surgery and medications.
Macular Degeneration: This ailment is mostly age-related and is generally observed in senior adults. In such cases, retinal damage causes a loss of vision in the macula, present in the center of the visual field. These people are unable to read or identify faces, but retain some peripheral vision, and therefore, are not completely visually disabled.
Glaucoma: Glaucoma develops due to fluid pressure buildup in the eye. This intraocular pressure causes damage to the optic nerve, which disturbs the image transmission to the brain. If you have a family history of diabetes or glaucoma, you would be at a risk. It is advised that such individuals should seek medical advice after 40 to prevent long-term loss of vision, as symptoms of glaucoma are difficult to spot.
Cataract: Cataract refers to the fogginess that develops on the crystalline lens, which results in varying degrees of blurred vision. The opacity of the lens may be minor or it could be complete. Early warning signals include short-sightedness or myopia and a reduced ability to recognize shades of the color blue. Cataract is a condition that progresses with age, and can cause complete blindness if one does not undergo treatment.
Night Blindness or Nyctalopia
Night blindness, as most of us know, is a visual impairment which occurs in darkness. One may not categorize it as total sightlessness, but the loss of vision in these cases is quite substantial. Such people are unable to adjust their vision in dim lights or darkness. Night blindness can be present in some from the time they are born. In others, it may be a result of retinol or vitamin A deficiency or even eye injuries.
Another cause may also be retinitis pigmentosa, a genetic condition in which the rod cells which are present in the retina become gradually unresponsive to light. In later years, the daytime vision of such people is also known to deteriorate. This condition is mostly observed in youngsters, and they gradually become completely blind by the time they are 40.
The good news is that genetic testing can help determine the risk of retinitis pigmentosa. People with a family history of this condition can assess the chances of passing it on to their children, which can help families seek appropriate medical advice.
Color Blindness
Color-blind individuals lack the ability to discern certain colors. Mostly considered a genetic condition, it does not completely fall under the typical definition of blindness. Sometimes, exposure to ultraviolet light may cause retinal damage, resulting in color blindness. Such people usually suffer from red-green color blindness, which means that they have problems to differentiate between certain shades of red and green. In other instances, people might be unable to see some colors, this condition is called dyschromatopsia. Achromatopsia, on the other hand, is a rare type of color blindness where the person is completely unable to see colors.
Interestingly, more men are found to be color-blind as compared to women, owing to its genetic origins. It may also be noted that color-blind people tend to have normal vision otherwise, barring their inability to distinguish between some colors.
Before we get down to writing off
Blindness as an unfortunate weakness, there are a few points worth pondering about. For instance, don't sighted people often lose their way in unfamiliar areas? Don't you think that they are excessively dependent on vehicular assistance even for short distances? And let's not even get to discussing the amount of time they spend each day on "looking pretty". Putting it differently, purely from a philosophical point of view, being able to see is as much a blessing as it is a curse.
