Related to this, RK results can drift towards farsightedness in the ensuing years. Laser procedures, if any drift occurs, drift very slightly towards nearsightedness, which would be preferred. This is the standard visual acuity requirement to drive without restriction in most states. It is not perfect vision. RK is used with less frequency now that laser methods are available, and when used is usually restricted to 1 to 3 units of nearsightedness, the range in which the best RK results are found.
Light sensitivity is usually temporary.
The cornea is weakened considerably in the very early healing phases less so for the healed result. Risk of perforation of the cornea with significant injury to the eye is dramatically increased in the first weeks after the procedure. Even after prolonged healing the eye may be slightly weaker.