Sight as you age

The lens consists mostly of water and protein and when the protein clumps, it clouds the lens and reduces the light that reaches the retina. The clouding may become severe enough to cause blurred vision. Most age related cataracts develop from protein clumping.

A cataract is a clouding of the lens in the eye that affects vision. Most cataracts are related to aging. Cataracts are very common in older people. A cataract can occur in either or both eyes. It cannot spread from one eye to the other. In a normal eye, light passes through the transparent lens to the retina. Once it reaches the retina, light is changed into nerve signals that are sent to the brain. The lens must be clear for the retina to receive a sharp image. If the lens is cloudy from a cataract, the image you see will be blurred.

Although most cataracts are related to aging, there are other types of cataract:

• Secondary cataract: Cataracts can form after surgery for other eye problems, such as glaucoma. They also can develop in people who have other health problems, such as diabetes. They are sometimes linked to steroid use. 

• Traumatic cataract: Cataracts can develop after an eye injury, sometimes years later.

• Congenital cataract: Some babies are born with cataracts or develop them in childhood, often in both eyes. These cataracts may be so small that they do not affect vision. If they do, the lenses may need to be removed.

• Radiation cataract: Cataracts can develop after exposure to some types of radiation.

As we age, some of the protein may clump together and start to cloud a small area of the lens, this is a cataract. Over time, the cataract may grow larger and may cloud more of the lens, making it harder to see.

Researchers suspect that there are several causes of cataract, such as smoking and diabetes. Or, it may be that the protein in the lens just changes from the wear and tear it takes over the years.

How can cataracts affect one's vision?

Age-related cataracts can affect one's vision in two ways:

One; clumps of protein reduce the sharpness of the image reaching the retina. The lens consists mostly of water and protein and when the protein clumps up, it clouds the lens and reduces the light that reaches the retina. The clouding may become severe enough to cause blurred vision. Most age related cataracts develop from protein clumping.

When a cataract is small, the cloudiness affects only a small part of the lens. You may not notice any changes in your vision. Cataracts tend to grow slowly, so vision gets worse gradually. Over time, the cloudy area in the lens may get larger, and the cataract may increase in size. Seeing may become more difficult. Your vision may get duller or blurrier.

Second, the clear lens slowly changes to a yellowish/brownish colour, adding a brownish tint to vision.

When are you most likely to have a cataract?

The term 'age related' is a little misleading. You don't have to be a senior citizen to get this type of cataract. In fact, people can have an age related cataract in their 40s and 50s. But during middle age, most cataracts are small and do not affect vision. It is after age 60 that most cataracts steal vision.

The risk of cataract increases as you get older. Other risk factors for cataract include:

• Certain diseases such as diabetes.

• Personal behaviour such as smoking and alcohol use.

• The environment such as prolonged exposure to sunlight.

What can one do to protect his vision?

Wearing sunglasses and a hat with a brim to block ultraviolet sunlight may help to delay cataract. If you smoke, quit it. Researchers also believe good nutrition can help reduce the risk of age related cataract. They recommend eating green leafy vegetables, fruits and other foods with antioxidants.

If you are age 60 or older, you should have a comprehensive dilated eye exam at least once every two years. In addition to cataract, your eye care professional can check for signs of age related macular degeneration, glaucoma, and other vision disorders. Early treatment for many eye diseases may save your sight.

The most common symptoms of a cataract are:

• Cloudy or blurry vision.

• Colours seem faded.

• Headlights, lamps, or sunlight may appear too bright. A halo may appear around lights.

• Poor night vision.

• Double vision or multiple images in one eye. (This symptom may clear as the cataract gets larger).

• Frequent prescription changes in your eyeglasses or contact lenses.

These symptoms can also be a sign of other eye problems.

The symptoms of early cataract may be improved with new eyeglasses, brighter lighting, anti-glare sunglasses, or magnifying lenses. If these measures do not help, surgery is the only effective treatment. Surgery involves removing the cloudy lens and replacing it with an artificial lens.

A cataract needs to be removed only when the vision loss interferes with your everyday activities, such as driving, reading or watching TV.

Sometimes a cataract should be removed even if it does not cause problems with your vision. For example, a cataract should be removed if it prevents examination or treatment of another eye problem, such as age related macular degeneration or diabetic retinopathy. It is not as dangerous if it is been cared and treated well.