Understanding Eye Problems

After struggling with blurry vision for years, I finally realized that it was time to consult with a professional. Simply put, I was tired of dealing with the struggles of acting like I could see when I really couldn't. It was embarrassing, and I just wanted to be able to participate like normal. I was nervous for the eye appointment, but my doctor was incredible. He walked me through every aspect of the exam and calmed my fears about permanent eye damage. This blog is all about working with an optometrist to get the vision experience that you really deserve.

How Eye Doctors Measure Your Eyes For Contact Lenses


If you are considering contact lenses, and you have never had them before, you may be wondering how doctors fit the lenses to your eye. There is actually a part of your eye exam referred to as the "contact lens exam." Really, this is just a few extra steps that your optometrist (a.k.a., eye doctor) takes to get the exact measurements of your eyes. Here is how that part of the exam works.

First, Your Prescription

Before your optometrist can even take the measurements of your eyes, he or she has to get your prescription first. (If you do not need corrective lenses and just want to wear contacts for fun, your eye doctor may skip this part.) The eye doctor records your prescription (if applicable) and then begins using special instruments to measure your eyes.

Checking for Astigmatism

Astigmatism is a condition of the eye whereby your eye is shaped more like a football than a soccer ball. As such, it affects a contact lense's ability to stay put on your cornea. Special contacts for people with astigmatism are prescribed. Your doctor checks to see if you have this condition, and then he/she knows whether or not you will need contacts for astigmatism in one or both of your eyes.

Measuring the Diameter of Each of Your Corneas

The corneas are the raised center parts of your eyes. They cover the irises (colored parts) and pupils (black dilating centers) of your eyes. For a contact lens to fit correctly, your eye doctor uses a special scope to accurately measure the diameter of each of your corneas. Usually, the corneas are within a fraction of a millimeter wide of each other, so your eye doctor will record them as equal and prescribe a lens that is slightly larger or smaller than the recorded diameters.

Measuring the Depth of Your Corneas

Contact lenses cup your corneas and hold onto them. There are various depths of contacts because not everyone has really high or low corneas. This depth measurement is taken from the side, with you looking straight on to the wall in front of you. Some people can have very different corneal depths in their eyes, in which case the eye doctors will prescribe a specific lens size for each eye, giving the patients two different lenses to wear for their two different corneal depths. Since astigmatism can affect this measurement, it is why eye doctors like Webster Eye Care check for astigmatism first.


24 February 2017