When someone is wearing eyeglasses, it is safe to presume that their vision is imperfect, but it may not be apparent exactly what is impairing their vision. The three most common likely culprits are nearsightedness, farsightedness and astigmatism. To help their patients understand the difference between these refractive errors, the eye doctors at St. Michael’s Eye & Laser Institute in Largo, Florida briefly explain each type in this blog.
Nearsightedness is a condition in which the eye has difficulty seeing objects that are further away, but no problem seeing objects up close. The main cause is an eyeball that is moderately longer than normal, giving the eye a more oval shape. As a result, the incoming light focuses before it can reach the retina. This condition affects between 30% and 40% of Americans. Most have it starting in childhood, with the quality of their distance vision degrading until about the age of 20.
In many ways, farsightedness is the opposite of nearsightedness. With hyperopia, people have no difficulty seeing distant objects clearly, but experience blurriness for nearer objects. This typically occurs because the cornea is flatter than normal. As a result of the imperfect curvature, incoming light refracts behind the retina. About 5% to 10% of Americans have farsightedness, with most having it from birth. It can also get progressively worse with time.
If the cornea or lens of the eye has an abnormal curvature, this means that the light refracts improperly. Depending on the shape of the eye, this can hurt the quality of a person’s up-close vision, faraway vision, or both. Approximately one in every three Americans has astigmatism.
It is possible for people to have nearsightedness or farsightedness on top of astigmatism. Although rare, it is also possible for someone to have nearsightedness in one eye and farsightedness in the other.
Treating Refractive Errors
Prescription lenses like eyeglasses or contact lenses can help correct the vision of patients with nearsightedness, farsightedness, and/or astigmatism. The other solution is LASIK. Laser eye surgery is a great way to overcome refractive errors by correcting the curvature of the cornea for improved vision.
At St. Michael’s Eye & Laser Institute, we have the latest technology that can help us to correct eyes affected by nearsightedness, farsightedness and astigmatism. If you have always wanted to limit your dependency on prescription eyewear, come visit one of our LASIK specialists to see if you are a good candidate for refractive surgery. Book an appointment online or call (727) 585-2200.