What is Presbyopia?
Presbyopia is part of the natural aging process which requires all people to need reading glasses for near activities sometime after age 40. Surgical options to reduce our dependency on reading glasses are divided into two categories: procedures that result in monovision, and clear lens extraction, in which a bifocal artificial lens may be implanted in each eye of qualified patients.
Monovision refers to the dominant eye being corrected to see in the distance, and the nondominant eye being corrected for close-up activities, such as reading, computer work, or other close-up activities. Because the presbyopic eye is unable to see both at distance and near, one eye is assigned to perform each of these functions independently. Though the human brain rapidly adapts to this “monovision,” it does not allow for binocular vision (simultaneous vision from both eyes), and therefore, depth perception is notably diminished. Depth perception is immediately restored by wearing glasses which equalize the prescription, and therefore the vision in both eyes.
Procedures used to perform monovision correction for presbyopia include:
- LASIK (laser in situ keratomileusis)
- PRK (photo-refractive keratectomy)
- Phakic lens Implant (Visian ICL)
Utilizing the clear lens extraction procedure maintains depth perception by implanting a bifocal lens, providing BOTH distance and near vision in each eye.