How An Eye Doctor Tests For Astigmatism During An Eye Exam

What Is Astigmatism? 

A normal cornea should be more or less spherical. Someone with astigmatism, however, has a cornea that is shaped more like a football. This alters the way light is normally bent upon entering the retina, resulting in blurry vision.

Astigmatism is usually not a contracted condition; most people who have astigmatism had it since birth. Contrary to conventional belief, one cannot develop astigmatism by misusing their eyes, such as sitting too close to the TV or reading under poor lighting conditions. 

A common refractive error, astigmatism can be corrected in many ways, including prescription eyeglasses, contact lenses, and laser surgery. 

Diagnosing Astigmatism During An Eye Exam 

A comprehensive eye exam is essentially a long series of visual tests in which your eye doctor diagnoses for eye conditions and diseases that may be present. Three such tests can help detect astigmatism:

• Refraction test: There are two kinds of refraction tests. An automated refraction test, or autorefractor, is an instrument that shines a light into your eye and assesses how it bounces upon its entrance. An objective measure of refraction error, along with your prescription for eyeglasses and contact lenses, is automatically calculated. While convenient, automated refraction tests are not suitable for patients with certain eye conditions, such as poor fixation, unusually high refractive error, and cataracts. The manual version of the refraction test entails looking at an eye chart while your eye doctor places a series of corrective lenses in front of your eyes and asks you which pairs of lenses are the clearest. 
• Corneal topography: This technology maps a computerized image of the cornea. In a three-dimensional test, corneal topography can find distortions in the curvature of the cornea. In addition to diagnosing astigmatism, this test can identify malignant growths and help your eye doctor choose better-fitting contact lenses. Corneal topography is quick and painless. Resting your chin on a device, you will be asked to stare at a fixed target while a computer takes pictures of your eyes.  
• Keratometry: A keratometer is another instrument that can measure the curvature of your cornea. Keratometry can detect astigmatism but also keratoconus (a disease that affects the curvature of the eye), assess the feasibility of cataract surgery, and help with contact lens fitting. Like other tests for astigmatism, keratometry is also painless and involves looking at a fixed object or image with your chin resting on a device. 

Your Calgary Astigmatism Solutions 

Blurry vision can be caused by a host of eye conditions, one of which is astigmatism. Luckily, astigmatism is a well-known refractive error and can be usually corrected either via prescription eyeglasses, contact lenses, or laser surgery. Through a comprehensive eye exam, your eye doctor can determine the severity of your astigmatism and assign the most appropriate treatment option to correct it. 

Market Mall Optometry offers some of the most thorough and effective eye exams for diagnosing astigmatism in Calgary. Our optometrists and eye doctors administer these tests to all patients, including children and seniors. Book a comprehensive eye exam today by calling 403-286-4884 or by filling out the online contact form. 

FAQ

Q: How often should I visit my optometrist?
A: Adults over the age of 18 should visit their eye doctor once every two years. Individuals over the age of 65 should visit their eye doctor annually. 

Q: Can I go blind from astigmatism?
A: No. Astigmatism is not an eye disease or a health problem. While severe astigmatism may significantly detract from your quality of life, it cannot cause blindness. 

Q: How common is astigmatism?
A: Around one-third of the population has some degree of astigmatism, though people with mild forms of astigmatism may not need to wear prescription glasses or contact lenses or go through corrective surgery.