Astigmatism
You have a blurred distance and near vision? Difficulty with vertical and horizontal lines perception? Visual strain? Laser or implants eye surgery could improve your vision and give you freedom from glasses.
What is astigmatism?
Astigmatism is a common and generally treatable imperfection in the curvature of the eyes that causes blurred distance and near vision. It is often associated with other visual disorders such as myopia or hyperopia. In France, 15% of the population suffers from astigmatism.
How is astigmatism diagnosed?
We can diagnose astigmatism during a complete eye examination. Testing may include:
- Eye chart
You’ll be asked to read letters on an eye chart. This tests for visual acuity or sharpness of your vision at certain distances. - Phoropter
This is where you look through a large binocular-like device and tell your doctor which letter you can see better. Based on your answers, your doctor writes a prescription to provide you with the clearest vision possible. - Autorefractor
This device also helps measure your astigmatism or other refractive error. It works by shining a light into the eye and measuring how it changes as it bounces off the back of the eye. - Keratometer
A keratometer measures the curve of your cornea. Your eye doctor may also do a corneal topography scan, which helps find imperfections and distortions on the corneal surface.
What causes astigmatism?
The eye has two curved structures called the cornea and the lens that bend or refract light onto the retina, which makes the image that you see. In a perfectly shaped eye, each of these elements has a round curvature like a smooth ball. A cornea and lens with such curvature refract all incoming light equally to make a sharply focused image directly on the retina. If either your cornea or lens is egg-shaped with two mismatched curves, light rays aren’t bent the same, which forms two different images. These images overlap or combine and result in blurred vision. Astigmatism occurs when your cornea or lens is curved more steeply in one direction than in another. It is not known what causes astigmatism, but genetics is a big factor. It may also occur as a result of an injury to the eye or after eye surgery. It often occurs with near-sightedness or far-sightedness.
What are symptoms of astigmatism?
Astigmatism symptoms may include:
- blurry vision or areas of distorted vision
- eye strain
- headaches
- squinting to try to see clearly
- eye discomfort
How is astigmatism corrected?
If you have astigmatism, you have a wide range of options to correct your vision problem. There are three main ways to treat astigmatism: glasses, contacts, or refractive surgery. Eyeglasses and contact lenses work by refocusing light on the retina in the back of your eye so that you can see more clearly. Having surgery is the only way to permanently correct astigmatism. However, your type and degree of astigmatism, corneal thickness, age and other eye conditions are all factors in whether surgery is the best option, and if so, which type of surgery.
What are the different surgical techniques to treat astigmatism?
We practice two techniques here to correct your astigmatism: We use a laser to regularize the shape of the corneal surface, or we can insert an implant that optically corrects the defect. It is possible to treat astigmatism on its own, or alongside another visual defect such as myopia hyperopia and/or presbyopia. The treatment of astigmatism is therefore carried out simultaneously with the associated visual defect being myopia, hyperopia and/or presbyopia using the same operating method, either laser or implant.