Does LASIK Cause Dry Eye?
LASIK, like all procedures performed on the cornea (PRK, SMILE, and more) definitely causes at least a temporary decrease in the tear film in all eyes. This is not due to any problem with the lacrimal glands, but rather from the unavoidable damage during the procedure that the laser causes to the sensory nerves located throughout the cornea.
These tiny, almost invisible nerves are there to signal the lacrimal glands when they need to increase tear production/release. This is usually in reaction to any irritation or stimulus to the corneal surface, including the ache and blurring that can occur with a dry corneal surface. So, until those nerves regenerate over time, the message being sent to the lacrimal glands on how much tearing is needed gets muted.
While there is almost always a significant improvement in dry eye over a period of several months (and up to a year after LASIK), it seems likely there is never a complete 100% recovery. In most cases, especially among younger people who tend to be the ones seeking LASIK, this tear decrease is not very noticeable or significant. But among those people who are predisposed to getting dry eye conditions later in life (like arthritis and many of the auto-immune diseases), the compromise in tearing can be a problem.
J. Trevor Woodhams - Chief of Surgery, Woodhams Eye Clinic