July 12, 2007 -- The US Food and Drug Administration
monovision Lasik. Monovision is the process of correcting one
eye for distance vision and one eye for near vision to reduce the
need for reading glasses or bifocals for patients affected by presbyopia
- the inability of the eye to focus on near objects. For most people
the brain adjusts to the difference in perception between the two
eyes. Monovision can be provided with contact lenses or laser eye
Monovision is already available as an off-label use of the Lasik
laser. An off-label use is when a medical device already approved
for one procedure is used for another. Off-label use is a common
method by which doctors put medical devices to the best use for
"Monovision Lasik has been available off-label since approval
of the first laser used for conventional Lasik laser eye surgery,"
says Glenn Hagele, Executive Director of the Council for Refractive
Surgery Quality Assurance (USAEyes.org),
a nonprofit Lasik patient advocacy. "This FDA approval is not likely
to have any practical effect on the availability of monovision Lasik
in the United States, however patients can now have monovision
with the more advanced custom wavefront technology."
Custom wavefront Lasik creates a more accurate "fingerprint"
of the patient's vision to guide the laser during surgery,
commonly resulting in a more accurate outcome.
According to the FDA, people considering monovision Lasik should
first wear monovision contact lenses to determine if they can tolerate
having one eye under-corrected. Following monovision surgery, the
two eyes may not work together as well as they did before in some
patients, especially in dim light or when performing tasks requiring
very sharp vision or fine depth perception. Patients may need to
wear glasses or contact lenses for some activities such as night
driving or reading small type. Side effects may include glare from
bright lights, rings around lights (halos), light sensitivity, night
driving glare, ghost images, double vision and visual fluctuation.
Lasik, or laser in-situ keratomileusis, is a procedure in which
the surgeon cuts a flap in the outer layers of the cornea, removes
a small amount of the tissue beneath it with the laser, and then
replaces the flap.