Cataract
What is a cataract?
A cataract is a clouding of the eye’s natural lens. When the lens becomes cloudy, the light is blocked and scattered, and therefore the image we see is blurred. It can be compared to a window that is frosted, or “fogged” with steam. The amount and pattern of cloudiness within the lens can vary. If the cloudiness isn’t near the centre of the lens, you may not be aware that a cataract is present.
For most people, cataracts are the natural result of ageing. Cataracts are the leading cause of vision loss among adults 55 and over. Additionally, some children are born with cataracts.
Eye injuries, certain medications (i.e., steroids), and diseases (i.e., diabetes) can also cause cataracts. Up to 1/3 of smokers get cataracts.
How quickly a cataract develops varies among individuals, and may vary even between the two eyes. Most cataracts associated with ageing progress gradually over a period of years. Cataracts in younger people, and people with diabetes, may progress rapidly over a few months and cause vision to worsen. It is not possible to predict exactly how fast cataracts will develop in any given person, but the average age of cataract extraction in the U. S. is 72.
What are the symptoms?
- Blurred, hazy or fuzzy vision
- Feeling that there is a film over your eyes
- Excessive glare or halos around headlights when driving at night
- Increased sensitivity to sunlight
- Loss of ability to see brightness of colours
- Frequent changes in eyeglass prescriptions
- Difficulty with daily activities such as driving, reading, or golfing
The symptoms described above may not necessarily mean that you have cataracts. However, if you experience one or more of these symptoms, contact the practice for a complete exam.
Surgery is the only way an ophthalmologist can remove the cataract. However, if symptoms from a cataract are mild, a change of glasses may be all that is needed for you to function more comfortably. There are no medications, dietary supplements, exercises or optical devices that have been shown to prevent or cure cataracts. Sunglasses that screen out ultraviolet (UV) light rays or regular eyeglasses with a clear, anti‑UV coating offer protection from excessive sunlight to help prevent or slow the progression of cataracts.
Cataract surgery should be considered when cataracts cause enough loss of vision to interfere with daily activities. You and your ophthalmologist should decide together when surgery is appropriate.
During cataract surgery, the cloudy lens is removed from the eye. This is usually done under local anaesthesia and performed as an outpatient procedure. In most cases, the focusing power of the natural lens is restored by replacing it with a permanent intraocular lens implant. Through the use of careful measurements of the eye taken before surgery, your ophthalmologist may be able to select a lens power to correct for nearsightedness or farsightedness, helping to reduce dependence upon spectacles after surgery.
Your ophthalmologist performs this delicate surgery using a microscope, miniature instruments and other modern technology. There are multiple techniques of cataract surgery, most of which yield equivalent results.
Occasionally, laser therapy is performed after cataract surgery to remove scar tissue that forms. This is technically called a capsulotomy but is sometimes referred to as a “secondary cataract.”
Although it is a common misconception, lasers are not currently used to remove cataracts.
After cataract surgery, you may return almost immediately to all but the most strenuous activities. You will need to take eyedrops as your ophthalmologist directs. One or more postoperative visits to the consultant are needed to check on the progress of the eye as it heals. After about four weeks, you can have your spectacles updated so as to maximise the new clear vision you now have.