Cataracts: Types, Symptoms, Causes, Risks, Diagnosis, Treatment, Prevention and Outlook



The lens of the eyes is responsible for the refraction of light so that images seen by the eyes and perceived by the retina are clear. They are composed of protein and water and are located at the back of the iris and pupil. The formation of a cloudy matter in the lens is called a cataract. It hinders the lens from providing a clear picture of an object for the retina, causing poor eyesight or a wrong perception of light.

The case of cataracts is common among adults particularly aged 50 years and above, but younger people may also be susceptible to developing such eye condition depending on their health condition and lifestyle. Cataracts can be removed with surgery. If left untreated though, cataracts can eventually cause the occurrence of other eye conditions including glaucoma, which is often linked to blindness. Cataracts, especially severe ones, can be found alongside glaucoma in some patients.

A person with cataracts in the eye would often complain about having a blurry vision despite already using eyeglasses or contact lenses. A clouded vision is risky when a person is driving, especially at night.


Types of cataracts will differ according to the condition of the patient as well as when and where they started to form.

Cortical cataract

This type of cataracts starts in the lens’ periphery and eventually spreads to the center of the eyes, particularly in the lens cortex.

Subcapsular cataract

This refers to cataracts that formed at the back of the lens of the eyes.

Nuclear cataract

These cataracts form in the central zone of the lens. This type usually occurs in older adults. Patients with this type of cataracts often suffer from severe nearsightedness (myopia). Severe cases of this type are associated with a yellowish tinge in the eyes which further constricts the proper function of the eyes.

Congenital cataract

These cataracts form from birth or during early childhood.


The onset of cataracts may be unnoticeable to a patient until he visits an ophthalmologist for a checkup. The initial symptoms of formation of cataracts in the eyes include a blurry vision and poor eyesight at night.

The symptom that is apparent among patients with severe cataracts is more apparent vision impairment. These patients may be suffering from severe myopia, inability to recognize people’s faces, sensitivity to light, and increased difficulty in seeing or driving at night. Other symptoms may be:

  • Perceiving light with “coronas”
  •  Frequent changing of lens prescription
  • Changes in the colors of images being seen
  • Double vision
  • Hazy perception of landscape


Some of the factors that contribute to the formation of cataracts in the eyes include:

  •  Accumulation of oxidants in the body
  • Dust, fumes, smoke (including when smoking)
  • Excessive exposure to ultraviolet radiation
  • Long-term medication or use of steroids
  • Health conditions (i.e. diabetes, rubella, galactosemia, myotonic dystrophy, neurofibromatosis type 2)
  • Trauma in the eye (previous eye injury, previous eye surgery)
  •  Aging
  • Genetics–If another family member has or had cataracts, it’s highly likely other family members will also have the eye condition.
  • Previously underwent radiation therapy

5Risk factors

Many people develop cataracts in their old age, but the likelihood of it to occur sooner or later depending on a patient’s case.

Health condition

Apart from the likelihood of people to develop this eye condition due to their health condition or diseases, people may increase their chances to develop it due to the necessity of taking drugs for a long time. Some of the drugs that increase a person’s likelihood of developing cataracts include steroids and statin medicines. Some treatments including radiation therapy can also cause the formation of cataracts. People who are obese or diagnosed with high-blood pressure are also likely to develop cataracts.


It has not been determined yet why cataracts are often linked with aging, but cases of cataracts are common among middle-aged and older adults.


People who are often exposed to ultraviolet light (prolonged exposure to sunlight), radiation, dust, and smoke are prone to developing cataracts.


Those who frequently drink alcoholic beverages in high amounts and/or are smokers are susceptible to developing cataracts in the eyes due to the body often struggling over oxidative stress. Oxidants can cause the formation of cataracts.

Previous eye condition

Previous cases of eye inflammation or eye injury can also leave a person prone to cataracts, especially if these previous cases of eye condition led the patient to undergo surgery.

Family medical history

If a person’s mother, father, or grandparent had or has cataracts, there is a high chance he will also have cataracts.


The ophthalmologist is often the first one who can tell the occurrence of a cataract in your eye through a series of eye tests. The formation of cataracts is associated with myopia, so patients who usually wear eyeglasses or contact lenses should bring those with them whenever they visit their ophthalmologist.

The eye tests the ophthalmologist will likely perform to determine the occurrence or onset of cataracts include:

Slit-lamp examination

This test involves the use of a lamp where the ophthalmologist will be able to see closely the structure of the eye for evaluation including the iris, cornea, and lens. This test may be enough for a doctor to determine whether or not there are abnormalities in the eyes of a patient.

Visual acuity test

This is one of the usual eye tests that ophthalmologists perform to determine how well their patients see with their eyes. Part of the test is making the patient read the letters on a chart located at a distance or writings on a piece of cardboard.

Retinal exam

This test involves the use of a drop that will dilate the pupils of the eyes. It will help the ophthalmologist examine the condition of the back of the eyes including the lens and the retina.


The onset of cataracts may be left unnoticed, and so the immediate case of cloudiness of vision or difficulty in seeing may be prescribed lenses. Surgery may be offered, but this choice is only offered to people who have worsening or severe cataracts.

Surgery to remove cataracts is usually successful and can be done on an outpatient basis. Cataracts form in the lens, so surgery to remove cataracts would mean the removal of the lens as well. The surgeon will then replace the lens with man-made ones, also known as a plastic intraocular lens (IOL). Newer IOL implants allow people to see near and far objects. About 95% of people who underwent cataract-removal surgery reported clearer vision post-surgery of up to 20/40.

For those whose cases of cataracts are milder, surgery may not yet be recommended by their ophthalmologists. The immediate treatments that they may be given are preventing these cataracts from becoming worse. Some measures that may be advised include:

  • Wearing proper, accurate lens prescription
  •  Reading under a good light at all times
  • Wearing sunglasses or a hat
  •  Limiting driving at night


As of this moment, it is not clear what truly causes cataracts, but specialists have figured out the factors that may contribute to the worsening of cataracts. In order to prevent the worsening of cataracts, patients may be advised to:

  • Regularly visit their ophthalmologist. Once every two years is enough to tell whether a cataract has formed if it is worsening, and if surgery is needed. Adults aged 50 and above should visit their ophthalmologist at least once every year. If in case the ophthalmologist advises the patient to have cataracts removed, the patient should take this advice, as cataracts are usually associated with glaucoma, which causes the gradual deterioration of the eyes’ performance.
  •  Stay away from smoke and dust. If in case you are a smoker, then you should quit smoking.
  • Drink alcohol in moderation. Alcohol consumed in high amounts also increase a person’s chance to develop cataracts.
  • Look after your health. Some health conditions are linked to the development of cataracts. For example, a person is more susceptible to cataracts if he has diabetes, high-blood pressure, or rubella.
  • Eating more nutritious fruits and vegetables. These foods can help fight oxidants and reduce oxidative stress in the body. Oxidants can cause cataracts. Fruits and vegetables also help improve and maintain eye health. Vitamins and minerals that help reduce a person’s chances of developing cataracts include omega-3 fatty acids, vitamin C, and vitamin E as well as zeaxanthin and lutein, which are found in green, leafy vegetables.
  •  Wear eye protection. Excessive exposure to the sun, which also radiates ultraviolet light, can be harmful to the eyes and leaves them prone to developing conditions including the formation of cataracts.


Cataracts are treatable and are often survived by patients. Vision can be restored or improved by removing cataracts in the eyes. Most patients with cataracts who had surgery reported significant improvement in their eyesight. Patients who refuse to undergo surgery only increases their risk of straining other parts of the eyes as their vision is bound to get worse with the worsening of cataracts. They may eventually develop other eye conditions, such as glaucoma (can cause blindness).