Cataracts

• What is a Cataract?
• What can be done about Cataracts?
• What are the signs of Cataracts?
• What causes Cataracts?

One of the questions optometrists are often asked is:

"Are there any signs of Cataracts in my eyes?"

What is a Cataract?

Many people would be less concerned if they understood that cataract changes are one of the most common causes of poor vision in older eyes although not all cataracts cause vision problems.

Light entering an eye passes through the cornea, then into the eye through the lens (which sits behind the pupil) and is focused onto the retina at the back of the eye. In a normal eye light passing through the cornea and lens produces a perfect image on the retina. Nerve cells in the retina convert the light into electrical impulses that are interpreted as vision by the brain. If vision is blurred because light is not perfectly focused spectacles or contact lenses will give normal vision.

Cataracts are not a "growth" over the front of the eye, they are due to changes in the lens tissue which causes it to become less transparent. If the lens becomes cloudy and opaque then the eye has cataract. Cataracts do not cause pain or physical discomfort

Most cataracts are a result of ageing but they can also occur as a result of eye injury and some diseases. The hardening of the lens inside the eye with age is a normal change that happens to us all. However, in some eyes the lens also becomes cloudy and the eye develops cataract. Occasionally cataracts are present at birth due to problems during pregnancy or as a result of other factors affecting the development of the eye before birth.

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What can be done to help Cataracts?

Cataracts can be surgically removed and in most cases the vision after surgery to remove the cloudy lens is very good. However, if there are age changes at the back of the eye in addition to the cataract then surgery will not result in normal vision, although there is often still some improvement.

Cataract surgery usually involves fitting a plastic "intra-ocular" lens inside the eye as a part of the operation. Your eye surgeon carefully measures the length of your eye, using ultrasound, in order to choose an implant lens of the right power. Modern surgical techniques using intra-ocular lenses offer a permanent result although distance spectacles may still be necessary for best vision and you will need reading spectacles for near work.

What are the signs of Cataracts?

Having cataracts reduces vision because it is like looking through a dirty window. In the early stages of cataract new spectacle lenses will often give good vision. Later, vision may become more foggy, less detail is seen, reading is slower, glare more of a problem and driving becomes especially difficult towards sunset and at night. At this stage new spectacle lenses may not restore normal vision.

As cataracts develop the opacities in the lens get larger and more dense causing the vision to become worse. Some cataracts change very slowly over many years while others may develop quickly in a matter of months. Often cataracts will affect both eyes but may develop more quickly in one eye compared with the other. There is no way of preventing age related cataracts.

What causes Cataracts?

Ultra violet (UV) light can damage the lens inside the eye. Research suggests that exposure to small amounts of UV over many years plays a part in the development of cataract. Sensible use of sunglasses and a hat will protect your eyes from UV.

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