Who Develops Astigmatism?
Astigmatism is often inherited, and is generally present from birth. It is a common vision condition that causes blurry vision. Just as perfectly aligned teeth are rare, so is a perfectly curved cornea. The degree of irregular curvature in your cornea determines whether you will need corrective lenses to help focus light rays better.
Having astigmatism that needs correction occurs frequently for both nearsighted and farsighted people. Certain types of eye surgery, such as cataract surgery, can increase your risk of developing astigmatism later in life.
Can Astigmatism Get Worse?
Astigmatism can get either worse or better over time. A comprehensive eye examination can identify whether you have astigmatism. And, if needed, your eye doctor can provide eyeglasses or contact lenses to correct your vision. Ask your doctor when he or she would like to see you next.
Your eye doctor will be able to tell if you have astigmatism after a regular eye examination.
There are several ways your doctor can test your eyes to not only diagnose astigmatism but to also determine how severe your astigmatism is and whether you’ll need corrective lenses:
A vision acuity test measures how clearly you see. Your eye doctor will ask you to identify letters of the alphabet printed on something called a Snellen Chart or on a screen that is a distance away. The letters become smaller as you move down the chart. Your doctor will test and assess each eye separately.
Lens Machine (Phoropter)
A lens machine allows your doctor to try out different corrective lenses in front of your eye. By measuring the light reflex from your eye through a handheld device called a retinoscope, he or she can see if there is a problem with your refraction, or how light hits your retina. Then, using the lens machine, your doctor can offer you different lens choices until you can see the eye chart clearly. This helps the doctor decide which prescription lens you need for each eye to correct your astigmatism.
Keratometry and Corneal Topography
Most optometrists and ophthalmologists have machines that can scan the surface of your eye to measure the curvature of your cornea. The keratometer gives your doctor information about the steepest and flattest curves of your cornea, helping to diagnose astigmatism and fit contact lenses. Corneal topography is an advanced technology that creates an even more detailed and accurate 3D digital map of your cornea.