Posted on: 06/20/17Lasik Surgery, Presbyopia, Refractive Surgery
In Denver & Fort Collins, we often address the vision issue of Farsightedness or Presbyopia.
Can you see distant objects clearly but find it difficult to see things that are up close, such as reading a book held at a normal reading distance? You may have either farsightedness or presbyopia. Both are similar symptoms and can’t be told apart without an eye examination.
What is the science behind vision?
Before going into the differences between farsightedness and presbyopia, it is necessary to understand the science behind our vision. The human eye is an incredibly complex organ made of the cornea, pupil, iris, lens and retina.
Cornea is the transparent structure at the front of the eye. This is the part that receives light from external sources. Under the cornea lies the iris, a ring-shaped membrane, which has a small, circular opening called the pupil. The iris can expand and contract to change the size of the pupil, which controls the amount of light entering the eye.
Directly ahead of the pupil lies the lens, which focuses the light on the retina, which is at the back of the eye. The lens changes its shape to focus the image exactly on the retina. The space between the lens and the retina is filled with jellylike tissue called vitreous humor. The retina is covered with millions of light-sensitive receptors that transmit the information to the brain. This is basically how our eyes work.
What causes farsightedness?
Farsightedness, or hyperopia, is caused by eyeballs that are too short, which prevents their lens from focusing on the incoming light on the retina, or by an abnormally shaped cornea or lens, which prevents light from entering the eyes accurately. This results in blurred vision when looking at things that are close up. It can occur in people of any age, including newborn babies.
The signs and symptoms of farsightedness include blurred vision when looking at objects that are close, inability to read, headaches, eyestrain and squinting.
What causes presbyopia?
Like farsightedness, presbyopia is the inability to see things that are up close clearly. Unlike farsightedness, it is an age related condition. Once the light enters the lens through the pupil, the lens changes its shape as needed to focus on the image on the retina. But as you get older, and especially after age 40, the lens loses its flexibility. As a result, it is unable to change its shape to focus on the image on the retina.
So how do you know if you have which one you have farsightedness or presbyopia? If the symptoms appear after the age of 40, then it’s most likely presbyopia.
How can farsightedness and presbyopia be corrected?
Both farsightedness and presbyopia can be corrected by wearing glasses and contact lenses. However, there is a better solution nowadays. Laser vision correction can correct both farsightedness and presbyopia permanently.