Astigmatism occurs when vision is blurred because the eye’s optics are unable to focus sharply on a specific object. This can be caused by an irregular curvature of the cornea or lens. This means that the rays of light that enter the eye are bent unequally, hence the distorted or blurred vision.
Irregular astigmatism is uncommon and may indicate a condition such as keratoconus (conical cornea). It is often better corrected with gas permeable contact lenses rather than spectacles.
It’s important to be aware that astigmatism is common, and some people are born with a degree of the condition. Sometimes, astigmatism can develop with age. Around 75% of all patients having laser refractive surgery have correction for astigmatism.
It is known that irregular astigmatism can be caused by scarring or keratoconus.
Very mild astigmatism might go unnoticed. A more significant case might cause symptoms such as blurred vision particularly in the distance, squinting, fatigue headaches. There is even a possible link between astigmatism and migraines.
There are several methods to determine the amount and axis of astigmatism. A keratometer can measure the curvature of the steepest and flattest meridians in the cornea. A retinoscopy will provide an estimate of the eye’s refractive error. Modern corneal mapping systems using topography give an accurate measurement of astigmatism facilitating planning of its surgical correction.
There are other measures that can accurately assess exactly the degree of astigmatism in any patient. Your optometrist or eye specialist can advise the best way to deal with the specific condition.
Fortunately, astigmatism can be corrected in a number of ways, including with glasses, contact lenses or refractive surgery. For more information on types of laser surgery, click here.