A cataract is the loss of transparency of the crystalline lens, the eye’s natural lens located behind the pupil. Rays of light pass through this lens to reach the retina, where images are formed. If the lens loses its transparency and obstructs the passage of light to the retina, the patient suffers from a progressive loss of vision.
The most common symptoms of cataracts are:
- Blurred vision, flashes, poor night vision
- This makes driving at night time difficult, and causes discomfort with light, and changes in prescription strength in glasses
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How to act?
- Cataracts cannot be prevented, but they can be detected by eye check-ups. It is advisable to see an ophthalmologist regularly, especially after the age of 45, to detect the possible existence of a cataract, its type, size and location, and to determine whether surgery is required and when it should be carried out.
Astigmatism is a refractive defect that causes images to focus on the retina in a distorted way, affecting near and far vision.
Astigmatism can occur by itself or in association with myopia or hyperopia, and is usually stable throughout life.
Most frequent symptoms
- Perception of distorted images (most common symptom)
- Problems in switching between near and far vision.
- Difficulties in seeing fine detail, either near or distant.
- Headaches, eye pain or dizziness, as a result of the eye’s muscular effort in trying to compensate for the defect with the accommodation of the crystalline lens (the eye’s natural lens whose elasticity enables the eye to focus). This is especially true in cases of astigmatism associated with hyperopia.
How to act
- Astigmatism can be corrected by glasses or contact lens.
- If the patient prefers not to wear glasses or contact lenses, surgical solutions are available.
Refractive surgery includes several treatments depending on the diagnosis:
- Excimer laser: applied to the thickness of the cornea, used to correct moderate astigmatism.
- Incisional technique (arcuate keratotomy). consisting of making incisions on the corneal surface, indicated for high astigmatism.
- Toric intraocular lenses: these can be phakic (implanted between the cornea and the crystalline lens) and pseudophakic (replacing the crystalline lens). They are normally used to correct high astigmatism.