Cataract occurs as a result of clouding of the naturally clear lens in the eye. A clear lens is essential to focus light, or an image, onto the retina (the photoreceptor). In a normal eye, light passes through a transparent lens to the retina. Once it reaches the retina, light is changed into electrical signals that are sent to the brain to be interpreted as an image. The lens must be clear for the retina to receive a sharp image. If the lens is cloudy (due to cataract), the image you see will also be blurred.
Causes of the cataract
Most cataracts are age-related. Majority of elderly people who are older than 60 years old will have some amount of cataract affecting their vision. It may be the result of a lifetime exposure to ultraviolet radiation contained in sunlight during their daily activities, or may be related to other lifestyle factors such as cigarette smoking, diet, and alcohol consumption. Cataract can also occur much earlier as a result of eye trauma, exposure to toxic substances / radiation, or following certain diseases such as diabetes mellitus. It can also be secondary to taking medication such as steroid for a long time.
A small minority of cataracts may even be present at birth due to genetic defects, developmental abnormality or exposure to diseases such as rubella during pregnancy. These are known as congenital cataracts.
What are the symptoms of a cataract?
Cataract started to develop in your eyes as early as 40 years old. Initially, most cataract is mild and do not affect vision. With time, cataracts worsen and eventually reduce your quality of vision in one way or the other. Symptoms usually develop over many years and these include:
- Cloudy or blurry vision.
- Colors seem faded.
- Glare with headlights, lamps, or sunlight.
- A halo may appear around lights.
- Poor night vision.
- Double vision or multiple images in one eye.
- If you wear glasses, you may find that they have become less effective and frequent change of your glasses or contact lenses is needed.
How is a cataract detected?
If you have problems with your vision, you should consult your ophthalmologist. They will be able to detect the presence as well as the severity of your cataract. Sometimes, cataracts are diagnosed during a routine eye test, even if you have had no visual symptoms.
How is a cataract treated?
Cataract can only be treated with a surgery which involves removal of the cloudy lens and implantation of an artificial biocompatible clear plastic lens, called an intraocular lens (IOL), into the eye
What can I do to protect my vision?
Unfortunately it is not possible to prevent cataract. Wearing sunglasses and a hat with a brim to block ultraviolet sunlight may help to delay cataract. Adopting a healthy life style with no smoking and excess alcohol consumption is also helpful. Researchers also believe good nutrition can help reduce the risk of age-related cataract. They recommend eating green leafy vegetables, fruit, and other foods with antioxidants.
In summary, if you are 60 years old or older, you should have a comprehensive dilated eye exam at least once a year for early detection of cataract, age-related macular degeneration, glaucoma and other vision disorder. Timely and appropriate treatment of cataract will improve your vision and allow you to enjoy a better quality of life.
By Dr Sim (Malaysia Eye Specialist)
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