If people are asked to name the five senses, the sense of sight often comes to mind first. References to vision and the eyes also show up frequently in casual conversation. Someone might estimate a certain distance by “eyeballing” it, and parents may ask the babysitter to “keep an eye” on the children. A person who takes a rest might “get some shut-eye” while those who have an “eye-opening experience” typically feel enlightened.
As we can see, the eyes are obviously important, and in an ideal world, they would always function properly. In reality, however, this is not always possible, and people may need eyeglasses Halifax to improve their vision.
How Does the Eye Focus?
Two parts of the eye, the lens and the cornea, are responsible for focusing images. The lens, which has both the shape and size of a piece of M&M’S candy, is a clear structure in the inner eye. The cornea, which has a dome shape, is located near the front of the eye on its surface.
When both of these parts of the eye are smoothly curved, they area able to refract (or bend) the incoming rays of light to create a sharply-focused image. This image is formed at the back of the eye on a structure called the retina.
What Causes Farsightedness?
Approximately 5 to 10 percent of Americans, including children and adults, are farsighted. Farsightedness (or hyperopia) is a type of refractive error. These errors occur when the light rays entering the eye are not able to be refracted properly due to a problem with the shape of the eye; this can result from a lens or cornea that is abnormally shaped (not smoothly and evenly curved) or from a change in the length of the eyeball.
In the case of farsightedness, either the lens or cornea is not sufficiently curved, or the eyeball is shorter than usual. Therefore, incoming light is not able to be focused directly on the retina, the images are focused behind the retina, and blurred vision results. Treatment options include prescription lenses or refractive surgery.