What is Astigmatism?
Astigmatism is a common refractive error or vision condition mainly caused due to irregular shape in the eye lens or cornea. If caused to cornea wherein the cornea gets irregular shape it is called corneal astigmatism and if caused due to the lens it is called lenticular astigmatism.
Normally when light enters the eye it bends (refracts) uniformly forming a clear image. In case of an eye with astigmatism only a part of the object gets focused at time as light gets refracted to multiple areas of the retina. This makes it difficult to see causing blurring in vision.
It is also referred to as a ‘cylindrical number’
What are the causes?
It could be hereditary, due to eye injury, eye surgery causing scarring in the cornea or other eye conditions such as keratoconus where the structure of the cornea changes from a normal shape to a cone shape. Some are born with astigmatism while some have it along with other refractive errors like nearsightedness (myopia) or farsightedness (hyperopia). The exact cause is still unknown.
What are the symptoms?
The common symptoms are as noted below.
- Blurred vision
- Eye irritation
These symptoms could be a cause for some other illnesses too.
How is Astigmatism diagnosed?
A comprehensive eye examination including tests in Visual acuity, Streak Retinoscopy, Keratometry, Refraction, Corneal topography helps to diagnose Astigmatism.
What are the correction options?
There are various corrections options where the main focus is to reshape your cornea.
The common correction options are as noted below.
- Spectacles – Traditionally spectacles according to the prescriptions with the desired lens are used to correct astigmatism. These are best when surgery is not advisable. A cylindrical number corrects astigmatism.
- Contact Lens – SoftToriclenses or gas permeable rigid contact lenses for high astigmatism are used to maintain the shape of the lens to correct astigmatism. Great care need to be taken in usage and maintaining them hygienically. Toric = astigmatism
- Refractive Surgery – In case you are the right candidate for refractive surgery then Astigmatism could be corrected by vision correction procedures. Some of the common procedures are listed below.
- Laser-assisted in situ keratomileusis (LASIK) – In this procedure the corneal flap is created using a microkeratome or a Femtosecond laser (bladeless LASIK). The shape of the anterior corneal surface is changed using excimer laser. It is a safe, quick and painless procedure if found suitable for your eyes.
- Photorefractive keratectomy (PRK) – During this procedure, the laser is used to reshape the cornea and change its curvature. It is an old procedure compared to LASIK and is currently used only when the cornea has had previous eye surgery, scars etc and not commonly as a primary line of management.
Astigmatism is correctable not preventable. It may worsen gradually if unattended. It may get unnoticed in children if they are not subject to regular eye checkups.
Blurred vision is a common symptom both in cataract as well as Astigmatism. Both are correctable and treatable in a single procedure.
Enhance your vision to permanent correction and spectacle free life.
If you notice any vision problems do get in touch with us for an eye check up and get the best correction suitable for your eyes.