Like a camera, the eye works by focusing light. When the lens cannot focus light properly you need glasses or contact lenses to assist.
Light enters the eye through the clear layer called the cornea, which acts like a lens by focusing the light. The light then travels through the natural lens of the eye and finally focuses on the retina at the back of the eye. The retina transmits information to the brain via the optic nerve where sight is then perceived.
Common refractive errors include Hyperopia (farsightedness), Myopia (nearsightedness), Astigmatism, Presbyopia (the need for reading glasses).
In almost all these cases, with the exception of Presbyopia, these errors can be corrected by use of Excimer Laser.
Common Refractive Errors:
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Image of long sighted eye
Farsightedness, or Hyperopia is when you can see things in the distance but have trouble up close. This occurs when the eye is too short in relation to the curvature of the cornea. Light rays do not focus on the retina, but instead focus behind it. In most cases, hyperopia can be corrected with Excimer Laser in our surgery.
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Image of short sighted eye
Shortsightedness, or Myopia is where close up objects are clear, but long distance objects become blurry without using spectacles or contact lenses. This occurs when the eye is too long in relation to the curvature of the cornea. Light rays do not focus on the retina but instead in front of the retina. In most cases, myopia can be corrected with Excimer Laser in our surgery.
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Image of astigmatic eye
Astigmatism occurs where your cornea is irregular in shape. A person with astigmatism generally sees all objects, near or far, in a blur or with distortion. Astigmatism occurs when the cornea has an irregular shape. This creates a distorted or uneven image because of the unequal bending of light rays entering the eye. Astigmatism can accompany farsightedness or nearsightedness. In most cases, astigmatism can be corrected with the Excimer Laser in our surgery.
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Presbyopia, or the need for reading glasses, is a normal condition which generally happens in the mid 40s. This is when the eye begins to lose the function of focusing on near objects. This happens as the crystalline lens inside the eye naturally increases in size and also becomes more rigid. The lens cannot change shape as easily to allow focus.
Presbyopia is corrected by the use of reading, bi-focal or multi-focal spectacles and contact lenses. Unfortunately, at this stage Presbyopia cannot be treated with Excimer Laser.
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Since the Excimer Laser treatment can only correct one refractive error in each eye, people who wear bifocals can have one eye corrected for close vision and the other eye for distance vision. This is called Monovision and allows both close and distance vision simultaneously.
Alternatively you can choose to have your eyes corrected for distance vision and continue to wear glasses fro reading.
Not everybody is suitable for Monovision treatment as it requires both a neural (brain) and visual (eye) adaptation period. To assess your suitability, we begin by giving you contact lenses which simulate the outcome, then decide if you are still able to do your normal activities, such as work, driving, and sports.
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The current generation of Multi Focal Intra Ocular Lens allows excellent sight for both near and distance vision. The great benefit of this lens has been the ability to read small print without spectacles
Some patients report slight haloing/star bursts around street lights, car headlights. However, all felt this minimal side effect was easily tolerated in view of the excellent near vision experienced.
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