While waiting at the bus stop, have you ever faced problems differentiating between digits 8, 6, and 9 on the approaching bus number display? Or observed dispersive light streaks from the street lights during night time? If yes, you are not alone!
The visual symptoms from both scenarios are typical presentations caused by astigmatism and myopia (or short-sightedness).
What is astigmatism?
Astigmatism is a condition whereby each of your eyes has 2 different refractive power (or short-sighted degrees) and this caused you to see objects and numbers with streak-like distortions. Another example to better explain astigmatism is that your eyes are shaped unevenly like a rugby ball rather than like a basketball, causing you to see things to be blurry and distorted!
What is the difference between astigmatism and myopia?
Myopia, on the other hand, is a condition of blur vision caused by the elongation of the eyeball. In this case, the eyeball of a myopic eye is shaped more like a basketball rather than a ruby ball! Symptoms of myopia include blur vision but do not cause as many distortions and visual induced headaches as compared to astigmatism.
You will need an eye examination by an optometrist to know if you do have both myopia and astigmatism.
How common is astigmatism and how do I prevent it?
There is no sufficient research data about the prevalence of astigmatism in Singapore, but many people with high myopia tend to have high astigmatism of more than -1.50 degrees! Some others, however, have less than -0.50 degrees of astigmatism or none at all. Astigmatism is usually hereditary and present since birth.
Other causes of astigmatism are:
1. Cornea (transparent frontal part of the eye) and other eye traumatic injuries
2. Hereditary cornea diseases(keratoconus)
3. Cornea infections from contact lens over-wear
4. Development of cataracts later in life(see article: cataracts: the issue of yellowing vision in Singapore)
Astigmatism is usually not preventable, but someone who does contact sports such as rugby and wrestling can make use of good protective sports goggles to prevent the risk of unintentional blunt trauma to their eyes.
Can astigmatism be corrected with glasses or eye surgeries?
Yes, definitely. Astigmatism can be corrected with both glasses and contact lenses. Most cases of astigmatism of up to -2.00 degrees can be corrected with high-index spectacle ophthalmic lenses. Astigmatism of up to -6.00 degrees can also be corrected with customised made spectacle lenses just for your unique eye prescription!
Considering spectacle-free options? You can also try out contact lenses that offer correction up to -3.50 degrees of astigmatism. Our range of Acuvue® Oasys brand of contact lenses by Johnson and Johnson vision care provides a clear vision for all-day comfort. Do make an appointment with us for a consultation on the right type of spectacles and contact lenses for you.
Eye refractive surgery such as LASIK corrects both short-sightedness and astigmatism. The procedures are performed by a specialist ophthalmologist in hospitals and medical clinics.
References:
Image: normal vs astigmatic eye. (2018, May 22). Heffington’s. https://heffingtons.com/what-causes-astigmatism/
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