What is Astigmatism?
Eye care specialists use many tests to accurately detect conditions such as astigmatism. They include visual acuity tests and an instrument called the keratometer.
Astigmatism can affect both near and far vision depending on the shape of your eye and how it bends (refracts) light rays.
Causes
Astigmatism occurs when your cornea or lenses have an irregular shape. This condition is also known as lenticular or corneal astigmatism. Its irregularity prevents light from focusing exactly onto the retina in the back of your eye. This leads to blurry vision, both near and farsighted.
The cornea or the lens should be shaped like a ball. This will allow light to enter evenly into your eye and focus sharply onto the retina at the back. With astigmatism, light cannot focus directly on the retina at the back of your eye. Instead, two focal points overlap, causing blurry vision.
Astigmatism may be hereditary, present at birth, or develop as a result of injury, surgery, and certain eye diseases such as keratoconus. A comprehensive eye examination with your eye specialist is the best way to diagnose astigmatism. They will use an instrument called a "phoropter" to test your vision before measuring your corneal curvature.
Symptoms
Eye care specialists are able to accurately diagnose astigmatism using a number of tests. They will examine your cornea and lens, the clear front part of your eyes, to see if it has an irregularly shaped shape that indicates astigmatism. If they do this, then you have corneal astigmatism. An unevenly shaped lens would indicate astigmatism.
Normal corneal and lenses should look like baseballs. They allow light to enter evenly while focusing on a single focal point in your retina. This results in clear vision. When you have astigmatism, your eyes can take on the shape of eggs or footballs. Light does not focus on a single focal point, and appears wavy.
Astigmatism often goes undetected in children, making it even more crucial to have regular eye examinations starting at the age of six. Uncorrected Astigmatism can negatively affect near and distance vision as well putting children at risk for a condition known as Amblyopia.
Diagnosis
Astigmatism is not always obvious, especially in younger children. However, if you notice your child squinting and rubbing his eyes often, or has blurry sight, it's time to see an eye care specialist. They will examine the entire eye (including the interior), perform visual assessments, refraction, and cross-cylinder tests (during this time your child will be looking at lenses of different strengths while looking at 360-degrees lines for crispest visibility) to diagnose astigmatism.
Contact lenses or glasses are often the best way to correct astigmatism. They allow light rays to fall correctly on the retina by bending them in a way to land directly at one focal point. There are hard and soft lens options, with rigid gas-permeable (RGP), which is more durable and offers better optics than soft lenses. Surgery is also an option depending on severity. For astigmatism it's usually done by LASIK, a laser eye surgery.
Treatment
Astigmatism can be treated with eyeglasses and contact lenses or surgery, depending on the best option for you. Your eye doctor can help you choose.
Normal eye anatomy consists of two perfectly curved surfaces – your lens and cornea – that work together to focus the light rays on the retina, allowing for clear vision. Astigmatism causes these surfaces to be irregularly curved, resulting in blurry images or distortions. This is one of three common refractive errors along with nearsightedness (myopia) and farsightedness (hyperopia).
Astigmatism can be corrected with contact lenses or glasses by compensating for irregularities of the corneal and lenticular curvatures. Refractive Surgery is an alternative. Most commonly performed procedure LASIK uses laser technology to reshape the corneas. LASEK or PRK procedures use alcohol directly on the corneas before laser technology is used.
Eye care specialists use many tests to accurately detect conditions such as astigmatism. They include visual acuity tests and an instrument called the keratometer. Astigmatism can affect both near and far vision depending on the shape of your eye and how it bends (refracts) light rays. Causes Astigmatism occurs when your cornea or lenses have…