Last week, in our first installment of a four-part eye disease series, we provided an in-depth discussion of the symptoms, characteristics and treatment of age-related macular degeneration (AMD).

Today we’re going to move on to the basics of cataracts.

To begin, a cataract is a clouding of the normally clear lens of your eye. Many people with cataracts say that seeing through these cloudy lenses is like looking through a foggy window. The foggy view can make it difficult to carry out daily tasks such as reading and driving a car (especially at night).

This eye disease develops slowly, and in the early stages doesn’t disturb a person’s eyesight. However, as time progresses, it eventually interferes with vision.

Causes of cataracts include:

  • Aging
  • An injury that changes the tissue that makes up the eye’s lens
  • Inherited genetic disorders which can increase a person’s risk of cataracts
  • Other medical conditions such as diabetes, past eye surgery or trauma
  • Long-term use of steroid medications

There are four types of cataracts:

  • Cortical cataracts – Affect the edges of the lens and start as whitish, wedge-shaped streaks on the outer edge of the lens cortex
  • Nuclear cataracts – Initially, this type of cataract makes a person more nearsighted or can even temporarily improve reading vision. However, over time, the eye’s lens gradually turns a dense yellow and clouds the vision.
  • Posterior subcapsular cataracts – This type of cataract starts as a small, opaque area that forms near the back of the lens, and often inhibits a person’s reading vision, as well as vision in bright light. Patients with posterior subcapsular cataracts frequently experience glare or halos around lights at night.
  • Congenital cataracts – In some cases, a person is born with cataracts or develops them during childhood. This type of cataract can be caused by an infection during pregnancy.

To determine if you have a cataract, it’s best to make an appointment with your eye doctor. At the appointment, your doctor will first review your medical history and symptoms and conduct an eye exam, which may include:

  • A slit lamp which allows the doctor to see a magnified view of the structures at the front of the eye
  • A visual acuity test (eye chart) to measure how well you can read a series of letters. This test is taken one eye at a time, while the other eye is covered. This basic test will show the doctor if you have 20/20 vision, or if are experiencing vision impairment.
  • A retinal examination will make it easier for the doctor to examine the back of the eyes (retina) and check for signs of a cataract

The most common cataract treatment is surgery – an outpatient procedure that takes an hour or less to perform. During the surgery, the clouded lens is removed. In some cases the cataract is removed and a clear artificial lens is implanted.

Consult your doctor about potential eye diseases, including cataracts, to learn more about the symptoms, types and treatment options.