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Clouding of the lens inside the eyes
The lens of the eye plays an important role in our ability to see clearly. Situated behind the iris and pupil, it works to focus light onto the retina to produce clear, sharp images. As old cells on the lens die, they sometimes clump together, causing the lens to cloud. This clouding of the eye's lens is called a cataract.

The formation of cataracts is a common part of the aging process. Fortunately, thanks to modern treatment techniques, cataract surgery is extremely safe and effective. It is also the most common surgical procedure performed, with six million procedures performed in the world each year.

Cataract Symptoms
Cataracts usually form slowly. The following are some of the first symptoms patients typically notice:
• Vision is blurred, hazy, cloudy, filmy, or foggy
• Light seems glaring and halos appear around lights
• Colours seem duller or different than usual (especially yellow)
• Vision changes (nearsightedness, temporary improvement in close-up vision)
• Difficulty reading and driving at night

Types of Cataracts

Age-related cataracts:

The formation of cataracts is very common as we age. By age 75, nearly everyone has at least one cataract.

Congenital cataracts:
Newborns sometimes have cataracts as a result of an infection that occurred in the womb.

Secondary cataracts:
Secondary cataracts form as the result of another disease, such as diabetes.

Traumatic cataracts:
Occasionally, cataracts can form after a traumatic eye injury.

Diagnosis and Prevention

According to the American Academy of Ophthalmology, adults between the ages of 40 and 64 should have a comprehensive eye exam every two to four years. People 65 or older should have a comprehensive eye exam every one to two years.
During an exam, an eye doctor will test your vision and will dilate your pupil in order to examine the condition of your lens and other parts of your eye. If cataracts are detected, you will be provided with treatment options.

Can cataracts be prevented?
Though there is no proven way to prevent cataracts, there are certain factors that are linked to their formation.
These include:
• Eye injuries
• Alcohol abuse
• Smoking
• Certain medications (including diuretics and corticosteroids)
• Diseases (such as diabetes)
• Long-term exposure to toxic substances, ultraviolet light, or radiation

Images and information related to Eye Conditions on this website have been kindly provided courtesy of St. Luke's Cataract & Laser Institute and adapted for the International Guide Dog Federation website. This on-line information is for educational and communication purposes only and should not be construed as personal medical advice. Information published on this website is not intended to replace, supplant, or augment a consultation with an eye care professional regarding the viewer/user's own medical care. The International Guide Dog Federation disclaims any and all liability for injury or other damages that could result from use of the information obtained from this site