Millions of people around the world have difficulty with eyesight. In America alone, there are currently more than 47 million people aged 20 years old and above who are nearsighted. Worldwide, it is estimated that more than a billion people are suffering from nearsightedness. Billions of dollars are being spent for research and treatment of these visual problems. A huge part of the expenses is on manufacturing and distribution of eye glasses.
A brief overview of the different kinds of visual problems
The most prevalent kinds of vision problems are refractive errors. Refractive errors are conditions wherein the person is still able to see a visual field, but he is having difficulties in focusing. Below are the 4 kinds of refractive errors:
Nearsightedness is referred to in the medical field as myopia. As the name implies, the person who has this is able to clearly see things that are near to him. The visual impairment begins if the object he is trying to look at is far away. The overall visual plane and not only distant objects will seem blurry to someone with Myopia.
Farsightedness, on the other hand, is referred to in the medical field as hyperopia. Again as the name implies, someone with a hyperopic type of refractive error is has difficulty in focusing on near objects. However, a visual plane that is far will seem normal.
Someone with astigmatism will see the world in a very blurry manner whether if the object is near or far. This is caused by an irregularly shaped cornea—the front surface of the eyeball. An irregularly shaped cornea disallows proper focusing of light that enters the eyes to the retina—the receptors at the back of the eye responsible for receiving information from light and submitting them to the brain.
Presbyopia is similar to farsightedness in that the person will find it difficult to focus on objects that are near. In hyperopia, the structural abnormality is within the cornea and the overall shape of the eyeball. With presbyopia, the problem is with the lens.
The most popular solution to refractive errors
To date, the most widely used solution to visual problems is still prescription glasses. However, there are various advancements in the science of visual care such as laser eye surgery and contact lenses. Even with the presence of these advance, though, a lot of people are still using eye glasses. In part, its popularity is continued due to a growing fashion trend which includes stylish glasses. What once was a device that would ensure a poor school experience of a child is now a source of envy among many fashionable people.
The different kinds of eyeglasses
- Polycarbonate lenses – these kinds of oculars are intended for athletes, workers that are prone to physical impact, and children (because of their natural clumsiness). They are strong and resistant to high velocity impact. They also have the ability to block-out UV rays.
- Trivex lenses – this kind of eyeglass lenses are made of a newly developed plastic that have been found to be stronger than polycarbonate lenses. Studies have also pointed out that this kind of lens offers better vision correction capabilities.
- Aspheric lenses – aspheric lenses are uniquely constructed in that it is composed of varying levels of curvature around the structure of the lens. This is to allow an overall flatter type of lens.