Most people who have radial keratotomy (RK) surgery
gradually become more farsighted for at least 8 to 10 years after surgery. This
is called the hyperopic shift. It is not clear what causes
the shift, how long it may continue, or how significant it may become.
The effect of the hyperopic shift depends on the person's age and whether
the person is nearsighted or farsighted after the surgery:
- People who are still slightly nearsighted after
surgery (undercorrected) may find that their distance vision improves gradually
as the hyperopic shift occurs.
- People younger than
40 may not notice the hyperopic shift, because their eye
can adjust to the change.
- People around age 40 may develop
presbyopia sooner as a result of the hyperopic shift
and may need reading glasses.