When discussing matters of eyesight, it is common to hear phrases like: Myopia, Hyperopia, Retina, lens etc. thrown around. But does anybody actually know what any of these terms mean? The real truth is that most people just nod in agreement, without understanding some of the basic problems that might be causing vision impairment. In this article we will demystify some of the technical jargon. So, we can better understand our problem and work towards fixing it.
Let’s start with the eye. In order to understand the defects in our eyes, first we have to have a basic understanding of the eye’s components. We will be mainly concerned with five parts. The lens, cornea, pupil, iris and the retina.
The pupil is the black part right in the center of the eye. The pupil is in actual fact just the section through which light travels from outside into the eye.
The iris is the color part of the eye. It comes in various shades such as brown, green, blue etc. The iris works as the controls for the pupil. If there is a lot of light, the iris closes and lets less light in. When it is dim or dark, the iris will open to let more light in.
The cornea is the thin transparent part of the eye that covers the front of the eye – the pupil and the iris. The cornea is responsible for bending or refracting light.
The lens is located in the eye, behind the cornea, pupil and iris. It changes shape in order to focus light onto the back of the eye, which is the retina.
The retina is a tissue layer at the back of the eye. Light that gets pulled into the eye is reflected to the retina, where it converts light signals into neural signals, which tells the brain to interpret what we are seeing.
What is Myopia and Hyperopia?
Now that we understand how the eye works we can look at some of the main causes of vision problems.
First, we have Myopia, also known as nearsightedness. Myopia means that objects close to the eye are seen clearly BUT objects far away appear blurry. The reason for this is that light rays coming into the eye from objects far away, focus IN FRONT of the retina, instead of ON the retina. There are two main reasons the light focuses in front of, and not on the retina. 1) The eye is too long. 2) The lens is too strong. In both these cases you will have no problem reading a book, but a mountain in the distance will be blurry.
Next is Hyperopia, also known as farsightedness. Hyperopia is the exact opposite of Myopia, in this case objects that are far away are seen clearly but objects close up are blurry. In the case of Hyperopia, light rays coming into the eye from objects close by, focus BEHIND the retina, as opposed to ON the retina, where it should. The reasons for this are the reverse of Myopia. 1) The lens is too weak. 2) The eye is too short. When you have hyperopia, watching a movie might not be a problem, but reading a text on your phone might be difficult due to a blurry screen.
How can they be corrected?
Hyperopia and Myopia can be corrected with various medical techniques. The most commonly known are the aid of glasses or contact lenses. But as we all know; these solutions are only temporary and also are conditional to you having the glasses on your face or contacts in your eyes. That’s why the only real solution for Myopia and Hyperopia is vision correction surgery.
When it comes to vision correction surgery, patients have a wide variety of options available to them. Each of them discussed here.