Your eye care professional will be able to tell if you have astigmatism after a regular eye examination.
There are several ways your eye care professional 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:
When you read a standard eye chart, you may have trouble telling the difference between letters and numbers that look similar, such as F and P or B and 8. With astigmatism, this may be the case no matter the size of the letters on the chart or your distance from it.
Keratometry and Corneal Topography
Most optometrists and ophthalmologists have machines that can scan the surface of your eye without touching it to measure the curvature of your cornea. The keratometer gives your eye care professional information about the steepest and flattest curves of your cornea, helping to diagnose astigmatism and fit contact lenses. Corneal topography is an even more advanced technology. It creates a highly detailed and accurate 3D digital map of your cornea for your eye care professional to examine on a computer monitor.
If you already wear glasses for nearsightedness or farsightedness, most eye care professionals will recommend adapting your glasses to correct your astigmatism, too. Even if it is mild, it is relatively easy to correct, and there is little reason not to. If you have astigmatism alone and it is severe enough to need correction, glasses should easily solve the problem.
Contact lenses that correct astigmatism are called toric lenses. The eye exam for astigmatism contact lenses may take longer than for other contact lenses, and you may need to try more than one pair of lenses to find a brand and type that doesn’t rotate too much and feels comfortable on your eye. Therefore, both the exam and the lenses typically cost more than regular contact lenses.
This surgical procedure involves making tiny cuts into the cornea to relax the steepest curves. These tiny cuts are typically called limbal relaxing incisions. Astigmatic keratotomy is effective, but laser surgery might be the better option for higher degrees of astigmatism.
Laser Eye Surgery (LASIK)
During LASIK surgery, the surgeon uses a laser to gradually reshape the cornea. By doing this, the eye care professional can sculpt your cornea to a more spherical shape and fix the refractive error that causes astigmatism.
Astigmatism-Correcting Cataract Surgery
If you have begun to develop cataracts, ask your doctor if and when cataract surgery may be right for you, and whether astigmatism-correcting intraocular lenses (IOLs) are an option. IOLs replace the eye's natural lens and can potentially correct both astigmatism and cataracts at the same time.
If you decide on a surgical treatment, you will need to be tested and evaluated before the procedure. Tests will likely include measuring eye pressure, pupil dilation, refraction and corneal thickness. Your surgeon will also evaluate your medical history to make sure you are an ideal candidate.
Your surgeon will provide you with specific details ahead of time about what to expect before, during and after the procedure. He or she will also be able to answer any questions you may have.
If you currently wear gas permeable contact lenses, you will not be able to wear them for three weeks before your evaluation. Other kinds of contact lenses shouldn’t be worn for at least three days beforehand.
Life After Surgery
Immediately after the procedure, your eye may be sensitive to light for a few hours. You will be prescribed eye drops to prevent infections and reduce any irritation you may feel.
Many people notice improvement in their vision the day after LASIK surgery. However, it typically takes a few weeks for the results to completely stabilize.
Severe astigmatism can only be reduced, not eliminated. If you have severe astigmatism, your doctor will wait a month before writing a new prescription for your glasses or contact lenses.