What Is a Cataract?


A cataract is a common eye condition characterized by clouding of the eye’s lens and may affect one or both eyes. Cataracts usually occur as a result of the normal aging process, most commonly affecting people over 50 years of age. However, in very rare cases, babies are born with cataracts or they develop during early childhood. In some cases, cataracts may develop as result of injury, in association with certain diseases such as diabetes, or long-term steroid use.

Cataract Symptoms

Since most cataracts are a natural part of the aging process they cannot be prevented. However, the risk of developing them may be reduced by protecting the eyes from sunlight and not smoking. Cataract symptoms often develop slowly. Initially, patients may not even realize they have a cataract. However, as the lens becomes gradually more opaque, symptoms may include:

  • • Blurred, hazy or misty vision
  • • Sensitivity to light – patients may find it more difficult to see in either dim or very bright light
  • • Colors may look ‘washed out’ or ‘faded’, or there may have a yellow tinge
  • • Double vision
  • • Glare from bright lights, or a halo effect, e.g. when looking at oncoming car headlights or street lamps
  • • Simple, everyday tasks and reading or watching television may become more difficult
  • • Spectacles or contact lenses may become less effective

Treatment of Cataracts

Any type of opacity in the natural lens is irreversible. If left untreated, cataracts cause severe visual impairment, eventually leading to blindness. Consequently, cataracts must be treated by extracting the eye’s natural lens and implanting an artificial one made from soft polymers or plastics, known as an intraocular lens.

Cataract surgery is one of the most common forms of surgery, with approximately 30,000 cataract procedures taking place every working day in Europe and the United States alone, and almost 25 million surgeries performed globally each year.

During surgery, which usually takes approximately 15 to 20 minutes and is typically carried out on an out-patient basis under local anesthesia, the surgeon first makes a micro-incision of approximately 2 to 3 mm on the side of the cornea. An ultrasound probe is then inserted through the incision to break up the natural lens into tiny fragments – a process known as phacoemulsification. Once the emulsified lens has been aspirated, the intraocular lens, which has been folded, is inserted through the same incision. The intraocular lens unfolds once it is in place in the eye, and usually no stitches are required.

Modern cataract surgery improves or restores vision in at least 90% of patients, and is associated with low rates of complications. However, while removing the cataract, refractive outcomes are difficult to predict in some cases which may lead to dissatisfaction of patients aiming for a spectacle free vision.