In monovision, one eye, usually the dominant one, is focused at distance. The fellow non-dominant eye is focused at near. With both eyes open, the brain automatically picks the image that is best in focus.
A strategy for eliminating the need for bifocals or reading glasses, the goal is to achieve spectacle freedom with everyday visual tasks. Can be achieved through the use of contact lenses or iLASIK or PRK (ASA).
Careful pre-operative planning must be done which includes:
Determination of eye dominance, working distance
Simulation of monovision with loose lens test and/or soft contact lens is an option in some patients
Disadvantages of Monovision
May still need glasses for some visual tasks
Loss of some depth perception possible
Headache possible
Possible poorer night vision
Lasting effects unpredictable
Only tolerated by 50-70% of patients. Some patients request reversal of monovision with an enhancement procedure.