Cataracts

FAQs

What is a cataract?

A cataract is a common eye condition where the natural lens of the eye becomes cloudy, leading to blurred or distorted vision. This clouding is caused by the clumping of proteins in the lens, typically due to aging or other factors.

Age related cataracts may start to develop between ages 40 and 50, but they are most common in people aged 65 and older. As cataracts progress, they can gradually interfere with daily activities like reading, driving, and recognizing faces. The longer cataracts are left untreated, the more significant the vision loss tends to be, making cataract surgery time sensitive.

How are cataracts detected?

Cataracts are detected through a comprehensive eye exam that includes:

• Visual acuity test: This eye chart test measures how well the patient sees from various distances.
• Dilated eye exam: Drops are placed in the patient’s eyes to widen—or dilate—the pupils. An eye care professional uses a special magnifying lens to examine the retina and optic nerve for signs of damage and other eye problems. After the exam, near vision may remain blurred for several hours.
• Tonometry: An instrument measures the pressure inside the eye. Numbing drops may be applied to the eye for this test.

Your ophthalmologist also may conduct other tests to learn more about the structure and health of the eye.

What is the lens?

The lens is the clear part of the eye that helps to focus light, or an image, on the retina. The retina is the light-sensitive tissue at the back of the eye. In a normal eye, light passes through the transparent lens to the retina. Once it reaches it, light is changed into nerve signals that are sent to the brain. In order for the retina to receive a sharp image, the lens must be clear. But if the lens is cloudy from a cataract, the resulting image will be blurry.

Who is at risk for cataracts?

The risk of cataract increases as we age. Other risk factors for cataract include:

• Certain diseases (i.e, diabetes);
• Personal behaviour (such as smoking or overconsumption of alcohol);
• The environment (such as a prolonged exposure to ultraviolet sunlight).

How is a cataract treated?

The symptoms of early cataracts may be improved with new glasses, brighter lighting, anti-glare sunglasses, or magnifying lenses. But if any of these steps do not help, surgery may be the only effective treatment. Surgery involves removing the cloudy lens and replacing it with an artificial lens. A cataract only needs to be removed when vision loss interferes with everyday activities, such as driving, reading, or watching TV. An eye care professional will determine the best option. Sometimes, a cataract should be removed even if it does not interfere with 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. If a patient has cataracts in both eyes that require surgery, the surgery will then be performed unilaterally (on each eye at a separate time).

How do cataracts develop?

Age-related cataracts develop in two ways: First, clumps of protein reduce the sharpness of the image reaching the retina. Because the lens is mainly made up of water and protein, when the protein begins to clump together, it can cloud the lens and reduce light from reaching the retina. The clouding may become severe enough to cause blurred vision. Most age-related cataracts develop this way. When a cataract is small, the cloudiness affects only a small part of the lens, so you may not notice any changes in your vision. Cataracts tend to "grow" slowly, so vision can worsen gradually. Over time, the cloudy area in the lens may increase, and the cataract may grow, thus making seeing more difficult. Vision will become more dull or blurrier.

The second way in which a cataract can develop is when the lens begins to change colours, taking on a yellow or brownish hue. As the clear lens colours with age, vision may appear to be browner. At first, the tinted vision may not be noticeable. But over time, increased tinting may make it more difficult to see clearly. The gradual change in colouration does not affect the sharpness of the image transmitted to the retina. Those with advanced lens discolouration may not be able to see blues or purples.

Are there other types of cataracts?

Yes. Although most cataracts are related to aging, below is a list of less-commonly occurring cataracts:

• Secondary cataracts: Cataracts can form after surgery for other eye problems, such as glaucoma. Cataracts can also occur in people with other health problems, such as diabetes. They are also sometimes linked to steroid use.
• Traumatic cataracts: Cataracts can sometimes develop following an eye injury. This may take years.
• Congenital cataracts: Some babies are born with cataracts or can develop them in childhood, often in both eyes. These cataracts may be so small that they do not have any effect on vision. But, if they do obstruct vision, then the lenses may need to be removed.
• Radiation cataracts: Cataracts can develop after exposure to certain types of radiation.