Definition and Overview

Eye cataract, or simply cataract, is a medical condition characterised by the clouding of the lens in the eyes resulting in blurring or loss of vision. A normal clear lens allows the light to pass through the back of the eye. With cataracts, the proteins in the eyes break down and the lens becomes cloudy, preventing adequate transmission of light. Cataract is very common and is the major cause of more than half of the blindness in the world.

Just like glaucoma, cataracts are usually associated with aging and can develop in one or both eyes. However, the two are not associated. Glaucoma is caused by damage to the optic nerve that could lead to vision loss without warning. Glaucoma symptoms include severe eye and head pain, hazy or blurred vision, and the appearance of rainbow-colored circles around bright lights. Glaucoma treatment, just like cataract, can include both laser and traditional surgery.

Causes of Condition

Cataracts can be caused by several factors. Of these, aging is the most common. Through time, the proteins in the eye lenses degenerate and degrade, resulting in what is seen as white spots in the eye. Other medical diseases, such as diabetes mellitus, as well as traumatic injury to the eyes, both penetrating and blunt, may result in the formation of cataracts as well. Other possible causes include significant radiation exposure, medications (such as steroids), infections (such as varicella and rubella), and cigarette smoking. Genetics also play a role in the development of cataracts. Congenital cataracts may also occur in children and is typically a component of a genetic syndrome, such as Down syndrome, Turner's syndrome, Edward's syndrome, and Alport's disease, to name a few.

Symptoms of Cataracts

The process of protein deposition in cataract formation is gradual. Thus, cataracts typically develop slowly through time. Because of this, many patients do not notice the symptoms immediately. The major and most prominent cataract symptom is blurred or reduced vision. The symptoms vary depending on the kind and the location of the cataract. Aside from blurring of vision, cataracts also usually lead to progressive nearsightedness, as well as difficulty in seeing at night or distinguishing colors, and even doubling of one's vision. These symptoms can lead to functional difficulties and can be debilitating at times.

Who to See and Types of Treatments Available

Treatment for cataracts is surgery. If you are experiencing a reduction in your vision, the first step is to consult an ophthalmologist or an eye doctor. Make sure to bring your prescription glasses or contact lenses during your consult. A comprehensive eye examination, which includes testing for visual acuity, as well as fundoscopy and dilated eye examination, will be conducted to identify the causes of your condition. If the cataract is confirmed, the ophthalmologist may initially attempt to increase the prescription of your corrective glasses or lenses. If this fails, cataract removal surgery will be recommended. Vision loss due to cataracts may be restored to near normal with this operation.

There are different types of cataract surgery including phacoemulsification, which is the most common. In this operation, ultrasound energy is used to break down or emulsify the cataract. The cataract is then suctioned out, and a prosthetic lens is inserted in its place.

Another kind of cataract surgery is extracapsular cataract extraction, which is recommended for patients with cataracts that are hard. This involves the manual removal of the lens while the capsule is left intact. An intraocular lens or IOL is inserted after lens removal. After the cataract surgery, you will be advised to wear an eye patch and to put on an eye shield at night. Cataract surgery is an outpatient procedure. Recovery is usually fast and complications, such as endophthalmitis and retinal detachment, may happen but are uncommon.

A breakthrough in cataract treatment is called laser eye surgery, which uses advanced femtosecond laser technology. It involves delivering near-infrared light to fragment the cataract into tiny segments prior to removal. The use of femtosecond laser procedure in the treatment of cataract is approved by the US FDA. As such, it is proven safe even for patients with other eye conditions such as age-related macular degeneration (AMD). Contrary to few studies that suggest cataract surgery can make AMD worse, most definitive research indicates that it has no direct effect.

Unfortunately, there is currently no scientifically proven way to prevent cataract formation. Thus, it is important to have regular eye examinations with your ophthalmologist. Several sources recommend an annual eye examination for people who are 50 years and older. For patients who have other existing medical diseases, they may have to consult their ophthalmologist more frequently. This allows you to detect the disease early on in its course, allowing prompt treatment and preventing the development of blindness.


  • National Eye Institute.

  • Singapore National Eye Centre.

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