1. What is a cataract and what are the symptoms?
A cataract is a clouding of the lens, a structure located behind the iris, the colored portion of the eye. Like the lens in a camera, the lens in the eye helps to focus an image onto the retina, which lines the back of the eye. When clouding occurs in the lens, vision is blurred. In addition to foggy vision, other symptoms of a cataract include glare, double vision, and difficulty with vision at night.
2. How is a cataract diagnosed?
A cataract usually cannot be seen by the naked eye. An ophthalmologist (an M.D. specializing in diseases and surgery of the eye) can dilate the pupil and examine the lens using a special microscope to determine whether a cataract is present.
3. What causes cataracts and how can they be prevented?
In the U.S., cataracts are most often related to aging of the lens within the eye. Other factors that can contribute to cataract formation include chronic use of steroid drugs, or previous eye surgery, injury, or inflammation. Ultraviolet (UV) light may also hasten the development of cataracts and UV-blocking sunglasses may slow the progression of cataracts. No medications, exercises, or dietary supplements have definitively been shown to slow or prevent cataract formation; however, a healthy, balanced diet rich in antioxidants such as Vitamins C and E is recommended.
4. When is it advisable to perform cataract surgery?
The timing of cataract surgery depends to a large extent on your visual needs. A person who relies on sharp vision for occupational needs (like an airline pilot) may need cataract surgery at an earlier stage than an older person who is functioning well with his level of vision. Cataract surgery can be performed when the vision has decreased sufficiently to interfere with everyday tasks or occupational activities and when the ophthalmologist determines that cataract surgery has a good chance of improving vision. Although it is not advisable to operate on a very mild case; however, one should not wait until a cataract has ripened to a very advanced stage, since these cataracts are much more difficult to remove.
5. Can a person become blind if cataract surgery is delayed?
Although vision will become severely impaired from advanced cataracts, this “blindness” can often be reversed with cataract surgery. Your ophthalmologist can also examine your eye to determine if there are other causes for the blindness.
6. What is a lens implant and why is it recommended?
After a cataract is removed, the eye lacks the lens that is needed to focus light. To restore this function, a plastic lens implant (also known as an intraocular lens, shown to the right) is inserted. These lenses are extremely durable and can last a lifetime.
Depending on your needs and desires, a basic lens implant or a high-performance implant such as the Alcon AcrySof® Toric or PanOptix® can be used. Discuss these options with your surgeon.
7. How is the implant selected?
Your surgeon will order a simple and painless test, which measures the length of the eye and helps to determine the correct power of the implant. Additional measurements of the corneal surface curvature are also taken for the calculation. Soft contact lens should not be worn 1 week prior to this measurements. Hard contact lens should not be worn 1 month prior to this measurements.
New high performance lenses are now available. Your surgeon can discuss with you whether these lenses might be right for you.
If you have astigmatism (blurring of your vision due to the oval shape of the eye), selecting the high performance Alcon AcrySof® Toric lens can counteract the astigmatism resulting in clearer vision without glasses.
The high performance Alcon PanOptix® lens can provide good vision for distance, intermediate and reading distances, and is many cases, reduce the need for glasses for most everyday tasks.
8. Why are glasses sometimes necessary after lens implantation?
While our calculations for lenses are excellent, it is not possible to determine the exact, final prescription of the eye until it has fully healed following cataract surgery. The lens implant usually provides 80 to 90% of the final prescription of the eye, and therefore vision without glasses is often quite good. However, to give the best possible vision, it is sometimes necessary to fine-tune the optical correction with glasses of regular thickness. Bifocals are usually needed to provide the sharpest vision for both distance viewing and reading small print. Glasses are usually prescribed four to six weeks after surgery.