Information on Cataract that You Must Know

In this article, we will learn what is cataract, types of cataract, causes of cataract, some tips to prevent cataract and about cataract surgery.

What is Cataract

Cataract is extremely common problem experienced by many people all over the globe. According to latest assessment by World Health Organization, "Cataract is responsible for 51% of world's blindness. Although cataracts can be surgically removed, in many countries barriers exist that prevent patients to access surgery. Cataract remains the leading cause of blindness. As people in the world live longer, the number of people with cataract is anticipated to grow. Cataract is also an important cause of low vision in both developed and developing countries."

What does cataract mean? WHO defines cataract as, "Cataract is clouding of the lens of the eye which prevents clear vision".

About Cataract

In a human eye, there is a lens made of proteins which helps in our vision. Let us take an example to understand this. You are reading this article from your PC or smartphone or tablet. Rays of light coming from the screen are incident to your eyes. These incident rays are being converged or focused at a single point by the lens on retina. Now, retina, the innermost layer of your eye will receive the stimulus of light and produce nerve impulses which will be interpreted by your brain and hence you can read my article. Cataract makes the lens cloudy or rather opaque which would prevent light rays from reaching your retina and hence you may not be able to read my article and you may turn blind. This doesn't happen suddenly but the rate of progression of disease may be different in each case. In few cases, cataract may be present since birth.

Cataract is mostly seen to be related to aging process but may be occasionally seen since birth or at young ages as well.

Types of Cataract

Now, let us discuss the the types of cataract. Cataract due to aging is very common.  There are three types of cataract:

• A subcapsular cataract occurs at the back of the lens. People with diabetes or those taking high doses of steroid medications have a greater risk of developing a subcapsular cataract
• A nuclear cataract forms deep in the central zone (nucleus) of the lens. Nuclear cataracts usually are associated with aging
• A cortical cataract is characterized by white, wedge-like opacities that start in the periphery of the lens and work their way to the center in a spoke-like fashion. This type of cataract occurs in the lens cortex, which is the part of the lens that surrounds the central nucleus.

Vision with cataract-affected eye

Vision with normal eye

Cause of Cataract and Risk Factors

When speaking about causes of cataract, the actual cause that causes cataract is not known. Researchers suspect that cataract may be caused by a variety of causes. However, there are certain risk factors for cataract. These risk factors are found to cause or to be associated with cataract development. These risk factors include :

•  UV radiation
• Diabetes
• Smoking
• Obesity
• Hypertension
• Significant alcohol consumption
• Previous eye injury or inflammation
• Previous eye surgery
• Family history
• Hormone replacement therapy
• Certain medicines

Symptoms of Cataract

Now, we come to symptoms of cataract. The age-related cataract develops at the age of 30s or 40s. At this time, you may not notice any of the symptoms of cataract. Symptoms of cataract develop only after certain years. Till then, cataract, even if present, may not affect your vision. Later, you may experience blurred vision, like looking through a cloudy piece of glass or viewing an impressionist painting.

A cataract may make light from the sun or a lamp seem too bright or glaring. Or you may notice when you drive at night that the oncoming headlights cause more glare than before. Colors may not appear as bright as they once did.

The type of cataract you have will affect exactly which symptoms you experience and how soon they will occur. When a nuclear cataract first develops, it can bring about a temporary improvement in your near vision, called "second sight."

Unfortunately, the improved vision is short-lived and will disappear as the cataract worsens. On the other hand, a subcapsular cataract may not produce any symptoms until it's well-developed.

If you feel that you have cataract, consult an ophthalmologist as soon as possible.

How is Cataract cured?

Let us now know about treatment of cataract.
At early stage, symptoms of cataract may be corrected using new eyeglasses, brighter lighting, anti-glare sunglasses, and magnifying lenses. If these corrections don't work, surgery is the only option for treatment of cataract. However the need for surgery, benefits, complications, and other things must be discussed with your ophthalmologist and you may together take this decision.

Cataract surgery is of two types, one which involves stiches called Extracapsular surgery and other which does not involve stiches called Phacoemulsification or in short Phaco. In both the surgeries, the damaged natural lens is removed and artificial lens called intraocular lens is implanted.

What can be done to prevent Cataract?

Finally, we come to prevention of cataract which is very important for all of us. For preventing cataract, all we need to do is protect our eyes from sunlight and include antioxidants, vitamin E and carotenoids to our diet. You can use sunglasses or wear a hat with brim to prevent sunlight from falling directly into your eyes. This will protect your eyes from harmful UV radiations. Higher dietary intake of vitamin E and carotenoids like lutein and zeaxanthin may reduce the risk of cataract. Other studies have shown that antioxidant vitamins such as vitamin C and foods containing omega-3 fatty acids may reduce cataract risk.