Overcorrection makes an eye that was
nearsighted before surgery
farsighted (hyperopia) after surgery. Overcorrection
speeds up the start of
presbyopia. Most people who have overcorrection will
need reading glasses around age 40. Improvements in
surgical techniques are reducing the risk of overcorrection.
Surgery to correct overcorrection is possible. But it is hard to predict
how well it will work.
Zinc is an essential trace mineral that's important for the immune system and the brain, as well as other parts of the body. In infants, zinc deficiency can delay normal development. At any age, serious zinc deficiency can lead to risk of infections.
Eye-related benefits. Zinc is believed to be important for vision because high levels of the mineral are found in the macula, part of the retina. Zinc enables vitamin A to create a pigment called melanin, which protects the eye. Some studies show...
With radial keratotomy (RK) surgery, the
number of people who are overcorrected or farsighted seems to increase as more
time (years) passes after the procedure. These changes over time are believed
to be caused by the
hyperopic shift. The hyperopic shift is less common in
people who have had laser surgery.
Primary Medical Reviewer
Kathleen Romito, MD - Family Medicine
Specialist Medical Reviewer
Christopher J. Rudnisky, MD, MPH, FRCSC - Ophthalmology
June 24, 2011
WebMD Medical Reference from Healthwise
June 24, 2011
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