Things to Know about cataracts and poor vision
What is a cataract?
Simply put, a cataract is an opacification or clouding of the lens of the eye. It leads to poor vision and eventually blindness. The risk of cataract increases with each decade of life starting around age 40. By age 75, half of white Americans have cataract. By age 80, 70 percent of whites have cataract compared with 53 percent of blacks and 61 percent of Hispanic Americans. Some good news, it is a cause of treatable/avoidable blindness. In essence, it can be treated by surgery.
How is a Cataract formed?
When you look at an object, light rays that enters your eye is focused by the lens on the retina ( a light sensitive membrane) producing a sharp image. As you age, the lens in your eye become thicker, less flexible and less transparent due to breakdown of tissues within the lens, these tissues clump together and cloud small areas within the lens, as it progresses the clouded areas expand eventually causing visual impairment. Cataract usually develops in both eyes but often at different rates.
Types of Cataract?
1. Senile Cataract: it is the commonest, related to aging
2. Secondary Cataract: Cataracts can form after surgery for other eye problems such as glaucoma. Cataracts also develop in people who have other health problems such as diabetes.
3. Traumatic Cataract: Cataracts can develop after an eye injury, sometimes years later.
4. Congenital Cataract: Some babies are born with cataract.
5. Radiation Cataract: Occurs after exposure to UV radiation.
What are the Signs and Symptoms?
You may notice blurred vision that is not corrected despite changing eye glass or contact lens prescription. Also there might be increasing difficulty with night vision, sensitivity to light and glare, double vision.
How is a Cataract detected?
You will need a comprehensive eye exam if you experience some of the symptoms listed above. The exam may include:
1. Visual acuity test: a Snellen’s chart is used to measure how well you see at various distances.
2. Dilated eye exam: drops are placed in your eyes to widen it and give the examiner the opportunity to examine your retina and optic nerve. You may experience blurred vision several hours after the exam
3. Tonometry: An instrument measures the pressure inside the eye.
How is a cataract treated?
Cataract usually develops over a period of time. Initially, depending on the stage of a cataract and impact of the cataract on your daily activities, eye glasses may be prescribed to give you the best vision possible. However, as the cataract progresses and vision diminishes, you may need to have a cataract surgery which in essence is removal of the opacified lens and replacing it with an artificial lens called intraocular lens.
Before surgery your doctor will carry out some tests which may include measuring the curve of your cornea and size and shape of the eye. This information guides the doctor in choosing the right type of intraocular lens(IOL).
Cataract surgery is usually done on outpatient basis, the operation lasts for an hour or less and is almost painless. After the operation, you will be monitored for complications such as bleeding before you are allowed to go home that same day. Remember to come with someone to drive you home.
After surgery, itching and mild discomfort are normal. However, avoid the urge to rub or press the eye. Your eye may also be sensitive to light and touch, you may also notice some fluid discharge. An eye drop will usually be prescribed to aid healing and lessen the risk of infection. Also an eye glass or shield should be worn to protect the eye.
Cataract surgery is generally safe and effective. Healing takes about eight weeks. When it affects both eyes, it is done one after the other.
Complications after surgery are rare but they can occur. These include infection as with most surgery, bleeding, pain, loss of vision, double vision. With prompt medical attention, these problems can be treated successfully. An after-cataract may develop months or years after cataract surgery, this is treated with a laser and it rarely results in further eye problems.
Dr S.A Aransiola
Kwara State, Nigeria.
Image source: Wikipedia