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What is cataract?
Cataracts occur as a part of the body’s natural ageing process. A cataract is a clouding of the eye's natural lens, which lies behind the iris and the pupil. This is the most common cause of gradual vision loss among people over the age of 40 years and is also the main cause of blindness in the world.
Cataract can occur in either eye or both the eyes. However, it does not spread.
How does cataract occur?
The lens in our eyes 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, where the light is transformed into nerve signals that are then sent to the brain.
The lens in our eyes is made up of water and protein. The protein is arranged in a way that keeps the lens clear, allowing the light to pass through. With age, however, the protein begins to clump which affects the lens and finally our vision. This is called cataract.
As age advances, the cataract grows larger and larger making it more difficult for us to see.
There are various types of cataract depending on how and where they develop in your eye:
- Nuclear cataracts are associated with aging and form in the middle of the eye lens and cause the nucleus, to become yellowish or brown.
- Cortical cataracts are wedge-shaped and begin at the outer rim of the lens and begin to grow towards the center. People with cortical cataracts often notice problems with glare or a "halo" effect around lights.
- Posterior capsular cataracts affect the back of the lens. They form faster than nuclear or cortical cataracts.
- Congenital cataracts are those that are present from birth.they may be caused by an infection contracted by the mother during pregnancy or by a genetic condition such as Fabry disease, Alport syndrome, or galactosemia. They are less common than age-related cataracts.
- Secondary cataracts is a condition which occurs after a cataract surgery and can be said to be a complication of cataract surgery. Once removed, cataracts cannot regrow. Secondary cataracts occur when corneal cells grow on the posterior lens capsule several months or years after the surgery. Fortunately, a highly precise surgical laser can remove the clouded capsule without the need for incisions. This process is very quick and discomfort free.
- Subcapsular cataracts progress very rapidly and affect the back of the lens, causing glare and blurriness. This type of cataract is seen in diabetes patients as well as patients who take steroids or suffer from extreme nearsightedness.
- Traumatic cataracts develop when an injury occurs to the eye. It can take several years for this to happen.
- Radiation cataracts can form after a patient radiation treatment for cancer.
Who is prone to cataract?
Some people are more prone to cataract than other people. They include:
- people who are 40 years and above. (though during middle age, most cataracts are small and do not affect vision. It is after age 60 that most cataracts steal vision.)
- diabetes patients
- patients taking treatment for cancer
- people who suffered from serious eye injuries
- people who overindulge in smoking and drinking alcohol
- people who suffer from obesity and high blood pressure
- people who take steroids
- people who are exposed to bright sunlight for long periods
What are the symptoms of cataract?
The symptoms of cataract include:
- Need for brighter light for reading and other activities
- Seeing halos around lights
- Clouded, blurred or dim vision
- Frequent changes in eyeglass or contact lens prescription
- Fading or yellowing of colors
- Increasing difficulty with vision at night
- Sensitivity to light and glare
- Double vision in a single eye
How is cataract diagnosed?
To determine whether you have a cataract, your ophthalmologist reviews your medical history and will perform an eye examination. He may ask you to undergo certain tests such as:
- Visual acuity test: In this test, an eye chart is used to measure how well you can read a series of letters. Each eye will be tested in turn and the doctor will find out if you have a 20/20 vision or if your vision is impaired.
- Slit-lamp examination: This examination is performed to look for any diseases or abnormalities in the anterior portion of the eye, which includes the eyelids, lashes, lens, conjunctiva, cornea, and iris. This test shows the eye structure in great detail.
•Retinal exam: In this exam, the doctor puts drops in your eyes to dilate your pupils. This makes it easier to examine the back of your eyes (retina) and check for any signs of a cataract.
What are the complications of cataract?
The complications of cataract if left untreated include:
- gradual loss of vision
- complete blindness
What is the treatment for cataract?
Surgery is the only way to remove cataracts. Based on your condition your ophthalmologist can guide you when to undergo the surgery. In the initial stages, cataracts usually do not require any surgery. It is when cataracts affect your daily life such as, keeping you from doing things you want or need to do that you need to consider undergoing the surgery.
How to prevent cataracts?
To reduce your risk of developing cataracts:
- wear sunglasses while venturing out to protect your eyes from UVB rays
- get regular eye exams done
- eat fruits and vegetables that contain antioxidants
- stop smoking
- exercise and maintain a healthy body weight
- keep your diabetes and any other medical conditions in check
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