What is cataract?
Cataracts occur as a part of the body’s natural ageing process. In this condition, clouding occurs in the natural lenses of the eyes, which lie 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 natural lenses in our eyes help 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 natural lenses in our eyes are made up of water and protein. The protein is arranged in a way that keeps each lens clear, allowing the light to pass through. With age however, the protein begins to clump which affects the lenses and finally our vision. This is called cataract.
As our physical 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 cataract is associated with ageing and form in the middle of the eye lenses and cause the nucleus, to become yellowish or brown.
Cortical cataract is wedge-shaped and begins at the outer rim of the lens in the eye and grows towards the centre. People with cortical cataracts experience symptoms of seeing blurry lines, or glare from the sun or from artificial lighting, which affect their vision.
Posterior capsular cataract affects the back of the lenses. They form faster than nuclear or cortical cataracts.
Congenital cataract is present from birth. It 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. This type of cataract is less common than age-related cataracts.
Secondary cataract 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 cataract is a condition 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 free of discomfort.
Subcapsular cataracts progress very rapidly and affect the back of the lenses, causing glare and blurriness. This type of cataract is seen in diabetes patients, as well as patients who take steroids or suffer from extreme near-sightedness.
Traumatic cataracts develop when an injury occurs to the eye. It can take several years for this type of cataract to develop.
Radiation cataracts can form after a patient undergoes 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 in middle-aged people, most cataracts are small and do not affect vision. It is after the age of 60 years that most cataracts start affecting the vision.)
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
people who have undergone ICL surgery
What are the symptoms of cataract? How is cataract diagnosed?
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 colours
Increasing difficulty with vision at night
Sensitivity to light and glare
Double vision in a single eye
To determine whether you have a cataract, your ophthalmologist reviews your medical history and performs 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 cataract.
What are the complications of cataract?
The complications of cataract if left untreated include:
gradual loss of vision
What is the treatment for cataract?
Surgery is the only way to remove cataracts. Based on your condition, your ophthalmologist can suggest 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 need to do, that you should 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
exercise and maintain a healthy body weight
keep your diabetes and any other medical conditions in check
Questions answered by trusted doctors
Did you know?
Statistics in India in 90’s
In India in the early 1990s, it was estimated that more than 80 percent of blind people, or more than 10 million individuals, suffered from bilateral cataract, and another 10 million individuals had cataract in one eye.
Cataract Blindness Control Program
In 1994, recognizing both the tremendous problem of adult blindness in India and the shortcomings in the existing cataract treatment program, the Cataract Blindness Control Program was begun in seven states in India where the need was most concentrated.
Impact Of the Program
A cumulative total of 15.35 million cataract operations were performed within the seven years of the program, which was successful in improving the quality of care.
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