Astigmatism, what is it?
Most people have some degree of astigmatism, yet many people are confused as to what astigmatism actually is.
In order to properly explain what astigmatism is, a little background information on how we see is needed. Light first enters through the cornea, which is the clear surface that covers the front of the eye. The cornea. in conjunction with the lens, is responsible for bending the light resulting in it focusing on the retina at the back of the eye. There are receptors on the retina that send signals which are processed by the brain which inturn allows us to form an image of what we’re seeing.
The cornea is perfectly round in a model eye, shaped like a basketball. With astigmatism, the cornea is oblong, shaped more like a football. This irregular shape results in light scattering and inturn focuses light onto several different points on the back of the eye. Clinically, this results in blurred vision at all distances.
Astigmatism, like other refractive errors such as myopia and hyperopia (near and farsightedness respectively) can be inherited with your genetics. It is typically present at birth and can increase or decrease over time. Sometimes astigmatism can be caused from trauma or an ocular disorder such as keratoconus.
Fortunately in most cases, astigmatism can be corrected with a variety of options. Some of the treatment options include:
- Contacts – Some people are under the impression that they cannot wear contacts due to their astigmatism. We fit several speciality lenses that can fit the majority of people in contacts, even with a high astigmatism correction
- Laser correction
- Ortho-keratology – a special contact that you wear at night to help reshape your cornea