Refractive errors occur when images become blurry when the eyeball is unusually long or short, or the cornea or lens is not evenly or smoothly shaped. The types of refractive errors are:
- Nearsightednesss (Myopia) – an eye condition where a person can see nearby objects clearly but has difficulty seeing objects at a distance. The eyeball is slightly longer than normal so the light rays fall in front of the retina.
- Farsightedness (Hyperopia) – an eye condition where a person can see distant objects well but has difficulty seeing objects up close. The eyeball is shorter than average so the light rays focus behind the retina.
- Astigmatism – an eye condition where a person has distorted and blurred vision at all distances. It is caused by an imperfectly shaped cornea that prevents light from focusing properly on the retina.
- Presbyopia – an age-related condition where the eye loses its ability to focus on nearby objects, making it difficult to read small text. It becomes noticeable in early to mid-40s and worsens as the persons grow older.
Many people suffer from a combination of either nearsightedness and astigmatism or farsightedness and astigmatism. These errors can develop in anyone and can be hereditary. They are usually accompanied by blurry vision, squinting and eye strain.
Patients suffering from refractive errors are usually recommended to wear eyeglasses, contact lenses or reading glasses. However, with the advancement of technology, a laser procedure can now be done to reduce or eliminate their use of eyewear.
- LASIK – LASIK is the most popular method of corrective refractive errors and eliminating the need for eyewear. It has two crucial steps – creating a corneal flap and applying laser energy to reshape the cornea. The flap is then returned to its original position.
- Supracor – Supracor is a revolutionary technology that can be used to reshape the cornea for both distance and near vision. It is ideal for patients over 40 years old, are suffering from presbyopia and want to be free from reading glasses. It can also be performed on patients who have had cataract surgery.
- Implantable Contact Lenses (ICL) – Unlike intraocular lenses, implantable contact lenses are surgically placed between the iris (the colored part of the eye) and natural lens, without having to remove the natural lens of the eye. These are recommended to patients with high degree of nearsightedness, thin or irregularly shaped cornea, or chronic dry eyes.
A refractive screening is highly recommended to evaluate whether the patient is a good candidate for LASIK. Aside from the eye grade, multiple tests are conducted to ensure the safety and accuracy of the treatment. Depending on the results, the surgeon recommends the proper treatment for the patient.