More than 3 out of 5 adults in the UK wear glasses (65%) or contact lenses (8%) to correct refractive errors.
We refer to refractive errors as short-sightedness, long-sightedness, or astigmatism. Their medical names are myopia, hyperopia, and astigmatism.
Many people are happy with their glasses or contact lenses in the last 2 decades advances in surgical techniques have proven to be an attractive alternative.
The refractive process in your eye is like the way a camera takes a picture. The cornea and lens in your eye act as the camera lens focusing rays of light on the retina which is like the photographic film. The image your retina “sees” is transmitted to your brain, which interprets the image. If the picture is not focused, the retina (or film) transmits a blurred image to the brain.
People with myopia or shortsightedness have an eye which is too long or a cornea that is too curved. The cornea is the transparent window at the front of the eye. That’s important because we tend to treat the cornea when we correct refractive errors. An elongated eye or a cornea that is too curved results in you seeing distant objects as blurry.
Blurriness happens because the lens focuses the image in front of the retina. You may be able to see close objects with clarity. You can likely read without glasses.
Myopia affects about a third of the adult population. At present, the majority of all laser eye surgery patients are myopic.
In presbyopic patients, we may advise treating shortsightedness by exchanging your natural lens with an artificial lens. We call that procedure Lens Replacement.
Hyperopia, or long-sightedness, is the opposite of myopia. You can see distant objects, but close-up objects appear blurred. Hyperopia results from an eyeball that is too short or a cornea that is too flat. Your cornea focuses images on a point behind the retina. LASIK or Laser Eye Surgery may help people with longsightedness too.
In presbyopic patients, we can treat longsightedness by exchanging your natural lens with an artificial lens. We call that procedure Lens Replacement.
Astigmatism is a condition in which an uneven curvature of your cornea blurs and distorts both distant and near objects. A normal cornea is round, with even curves on all sides, like a football.
The astigmatic cornea is more like a rugby ball, curved more in one direction than in another.
That uneven curvature causes light rays to have two focal point neither of which focuses clearly on the retina, blurring the visual image.
Most people have a slight degree of astigmatism, but a significant number need spectacle or contact lens correction to see clearly. Advances in technology and techniques allow us to correct astigmatism with LASIK.