Astigmatism Test: How to Know If You Have This Eye Problem

eye examination

Story at-a-glance -

  • One routine test that may help identify astigmatism is a vision test. Your doctor will ask you to read letters on a standard eye chart from 20 feet away. Those with 20/20 vision will be able to see what a normal eye can see 20 feet away
  • Another way for the doctor to identify the amount of astigmatism that you have is through a manual exam called retinoscopy. This entails shining a light into your eyes using a retinoscope while introducing a series of lenses between your eyes and the light manually

To identify whether or not you have astigmatism, you will need to go to a professional eye doctor to have your vision checked. This is important, especially if the symptoms are becoming bothersome as you do your everyday tasks.

Either an optometrist or ophthalmologist can correctly diagnose if you have astigmatism, and will usually conduct a series of tests to confirm your condition.

A Retinoscopy and Vision Test May Help Identify Astigmatism

Usually, routine eye exams are sufficient to detect astigmatism. The same instruments and techniques that are utilized for detecting farsightedness or nearsightedness can be effective in testing for this condition.

One routine test that may help identify astigmatism is a vision test. Your doctor will ask you to read letters on a standard eye chart from 20 feet away. Those with 20/20 vision will be able to see what a normal eye can see 20 feet away. However, if your vision is 20/80, you need to be 20 feet away to see what a normal eye sees 80 feet away.1

Another way for the doctor to identify the amount of astigmatism that you have is through a manual exam called retinoscopy. This entails shining a light into your eyes using a retinoscope while introducing a series of lenses between your eyes and the light manually.

Other Diagnostic Tests for Astigmatism

Today eye doctors conduct retinoscopies and vision tests along with other procedures that make use of automated instruments, which give them a faster preliminary test for refractive errors.2 These include:

Refraction – Also called subjective refraction or manifest refraction, this procedure makes use of a large lens machine called a phoropter, which contains multiple lenses that are placed in front of your eyes one at a time.

While looking through the phoropter toward an eye chart, the doctor will ask which of the lenses make the letters or image on the chart appear clearer. You need to answer these questions accurately, as this will determine your prescription.

Keratometry – This tests uses a keratometer, a machine that measures the bend in the middle of your cornea, identifying where the steepest and flattest curves are. The measurements derived from it help identify the shape of your cornea and how properly it can focus. A keratomer can also be helpful for checking the cornea after an eye surgery, as well as for fitting contact lenses.

Corneal topography – This is a highly advanced procedure that gives detailed information about the shape of your cornea. Your eye doctor will ask you to look somewhere specific, as the device collects thousands of small measurements.

Afterwards, a computer will use the data to produce a color map of your cornea, which your doctor will then use to plan corrective techniques for astigmatism. This procedure also works well for cataracts and keratoconus, and may also be used for fitting contacts.3

MORE ABOUT ASTIGMATISM

Astigmatism: Introduction

What Is Astigmatism?

Astigmatism Symptoms

Astigmatism Causes

Astigmatism Test

Types of Astigmatism

Astigmatism Treatment

Contact Lenses For Astigmatism

Astigmatism Prevention

Astigmatism FAQ



< Previous

Astigmatism Causes

Next >

Types of Astigmatism

Click Here and be the first to comment on this article
Post your comment