Understanding Cataracts

Definition of cataract

A cataract is cloudy, but a dense region that forms in your eye lens. A cataract forms when proteins in your eye clumps. The clumping prevents transmission of clear images from the lens to the retina. Your retina is a light-sensitive tissue that converts light signals from the lens into neural signals that can be sent through the optic nerve into the brain. A cataract does not develop all-at-once. It does so gradually and eventually distorts your vision. Sometimes cataracts may affect both eyes, but they develop separately. Cataracts are more prevalent in the elderly. According to the National Eye Institute, over half of the United States residents have cataracts or have undergone surgery for it by the time they are 80 years old.

Photo Credit: All About Vision

How do I know that I have cataract?

The following are important symptoms of cataract:

  • Difficulty seeing at night
  • Blurry vision
  • Colors appear faded even when they are not in reality
  • Your eyes become highly sensitive to glare
  • You frequently change your prescription glasses
  • Halos surrounding lights

Why do I have cataract?

There are several causes of cataracts. Common causes of cataracts include:

  • Excessive production of oxidants. Oxidants are chemically-altered oxygen molecules.
  • Ultraviolet rays
  • Smoking
  • Prolonged use of steroids and other medications
  • Radiation therapy
  • Trauma
  • Chronic diseases such as diabetes

Types

Cataracts are of different types. They are grouped based on their location and their pattern of development in your eye.

  • Nuclear cataracts develop in the mid-portion of your lens, causing yellowing or browning of the nucleus.
  • Cortical cataracts have the shape of a wedge and they develop around the edges of the nucleus.
  • Posterior capsular cataracts occur at the back of the lens. They develop faster than nuclear and cortical cataracts.
  • Congenital cataracts are present during birth. They develop within the child’s first year of life. However, they are rarer than age-related cataracts.
  • Secondary cataracts: these are caused by medications or diseases. Some diseases that trigger the formation of cataracts include diabetes and glaucoma. Medications such as steroid prednisone can also trigger cataract formation.
  • Injuries to the eye can cause the development of traumatic cataracts. However, the development of traumatic cataracts takes several years.
  • A person may develop radiation cataracts after exposure to radiation therapy for cancer.

Risk factors

The following are considered as risk factors for cataracts:

  • Alcoholism
  • Old age
  • Obesity
  • Smoking
  • Previous eye injuries
  • High blood pressure
  • Genetics (history of cataract in the person’s family)
  • Frequent exposure to the sun
  • Irradiation (from cancer treatments and x-rays)
  • Diabetes

How is cataract diagnosed?

Your doctor will carry out a comprehensive examination of your eye. The goal is to assess your vision and check for cataracts. Physical examination for cataract include an eye chart test, and tonometry (for measurement of eye pressure).

Tonometry flattens your cornea with a puff of air and then tests your eye pressure. It is usually painless. The doctor will also put some drops in your eye to enlarge your pupils. This will make it easy to examine your optic nerve and retina for eye damage.

Your doctor may also test your perception of colors and sensitivity to glare.

How are cataracts treated?

If you are not interested in surgery, your doctor may perform other treatments that help with symptom management. They may prescribe stronger glasses, sunglasses that have an anti-glare coating, or magnifying glasses.

Surgery for cataract

Surgery is advised when you can no longer perform your daily activities with ease due to cataracts. Surgery is also recommended when cataracts interfere with the treatment of other eye problems.

An example of surgery for cataract is phacoemulsification. This is a surgical procedure that involves the use of ultrasound waves to disintegrate the lens and take extract the pieces.

Another type of surgery for cataract is extracapsular surgery. It involves the removal of the cloudy part of the lens through a corneal incision. When the doctor is done with the surgery, he or she will replace the natural lens with an artificial intraocular lens.

Surgery for cataracts is generally safe with a very high success rate. Most patients return home the same day.

Preventing cataract

Tips for preventing cataracts or reducing your risk of developing cataracts include:

  • Having a regular eye examination
  • Wearing sunglasses to protect your eyes from ultraviolet rays
  • Stop smoking
  • Eat healthily (mostly vegetables and fruits that are loaded with antioxidants
  • Checking diabetes and other health conditions
  • Maintaining a healthy weight

Outlook

A cataract is a serious eye condition. If left untreated, it may result in blindness. Some cataracts may stop growing, but they won’t get smaller. The most effective treatment for this condition according to the National Eye Institute is surgery.

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