Many breastfeeding mothers have been told that Lasik eye surgery cannot be done until their child has weaned; sometimes it is recommended that the mother wait 3-6 months or longer after breastfeeding has ended before considering this surgery. These recommendations are based upon the idea that breastfeeding will cause changes in the curve of the cornea which will persist as long as breastfeeding continues. The concern with having Lasik surgery during lactation is that the surgery may need to be redone later if the mother’s vision changes after weaning. Although some women do experience eyesight changes during lactation, I was unable to find evidence to support the idea that all mothers will experience vision changes or that vision changes that do occur will necessarily persist throughout lactation. Some feel that a mother’s eyes will be back to their “normal” state once her periods have returned and are regular — many mothers reach this state long before weaning.
The curve of the cornea can change during pregnancy (due to hormonal changes), and there is at least one study that has documented similar changes during lactation. This is a small study (n=24) and the abstract does not indicate whether all of the women studied went on to breastfeed or how early they weaned:
Park SB, Lindahl KJ, Temnycky GO, Aquavella JV. The effect of pregnancy on corneal curvature. CLAO J. 1992 Oct;18(4):256-9.
I was curious whether there was more information on this, so I called Ruth Lawrence, MD, co-author of Breastfeeding: A guide for the medical profession (oral communication, August 2005). Dr. Lawrence said that the only reason to avoid Lasik surgery during lactation would be if the mother has temporary eyesight changes due to lactation (which sometimes happens).
A mother will most likely know if her eyesight has changed, as would her ophthalmologist or optometrist. If her vision has changed, Lasik surgery should be postponed until her vision has been stable for some time (because if her vision changes again she might need to have the surgery redone). Of course, one of the standard recommendations for Lasik surgery is that your glasses prescription has not changed in the last year, so this alone ought to exclude any women who do have vision changes during pregnancy and breastfeeding.
General information on Lasik surgery at the FDA website