Astigmatism
WHAT IS ASTIGMATISM?
Astigmatism is a common condition that results from imperfections in the curvature of your eyes. This can either be the curvature of the cornea (corneal astigmatism) or the lens (lenticular astigmatism) in the eye. Instead of being a perfect circle, the eye resembles more of a rugby ball shape. This causes light that enters the eye to be defocused.
Astigmatism can lead to symptoms of blurred vision, eye strain, squinting, and difficulty with night vision. It may also occur in combination with other refractive errors. These include myopia (near-sightedness) and hyperopia (far-sightedness).
HOW DOES ASTIGMATISM DEVELOP?
For many, astigmatism is often present at birth with genetics being a big factor. It may also develop later in life because of changes to the shape of the cornea/lens, injury to the eyes, or after surgery.
Individuals with a condition called Keratoconus can also develop a large amount of astigmatism. Keratoconus is a degenerative condition whereby the cornea of the eye progressively becomes thinner and becomes an irregular cone shape. It is an inherited condition that has a prevalence of approximately 1/2000 in New Zealand, with 60% of keratoconus being male. Eye allergies are common in individuals with keratoconus. This leads to a greater degree of eye rubbing which should be avoided as it can cause the condition to deteriorate more rapidly. Medications can be prescribed by Optometrists to reduce the symptoms of ocular allergy.
HOW DO WE DETECT ASTIGMATISM?
The best way to detect astigmatism is to book in for a comprehensive eye exam. A prescription check is carried out to determine the amount of astigmatic correction required.
Eye conditions like keratoconus are also diagnosed using a corneal topographer. This is an instrument that captures and displays an image of the cornea, creating a map that allows the practitioner to assess the curvature of the cornea and any irregularities.
WHAT CAN YOU DO TO FIX IT?
Astigmatism can be corrected in various ways, the first being glasses. Soft or Hard Contact lenses may also be used in the correction of astigmatism. Your Optometrist will be able to recommend the best option for you once a thorough eye examination has been completed.
Laser Eye Surgery (LASIK) can also be considered as a treatment for astigmatism. LASIK is a procedure involving lasers to reshape the cornea. This corrects the curvature of the cornea, allowing for light rays to be focused correctly to the back of the eye resulting in clear distance vision without the need for glasses or contact lenses. A referral can be made to an Ophthalmologist and the suitability of your prescription and cornea is determined by the surgeon.