As the eye ages, the lens becomes less flexible, causing the loss of near vision that is the hallmark sign of presbyopia in people over age 40.
During cataract surgery, a circular opening is cut in the anterior part of the lens capsule so the surgeon can remove the eye's natural lens that has become cloudy. The peripheral and posterior portions of the lens capsule are left intact, forming a partially open "bag" that the intraocular lens is positioned within to restore focusing power to the eye.
In a young eye, accommodation is essentially instantaneous and effortless.In a conventional IOL, the haptics are designed to keep the optical portion of the implant stationary, with no rotation or anterior/posterior movement that could affect vision.In a normal eye (without presbyopia or cataracts), this dynamic process of accommodation adjusts the focusing power of the eye by changing the thickness of the eye's natural lens.When the ciliary muscle is relaxed, the lens flattens to enable clear distance vision.
All IOLs have a central optical zone, with peripheral "legs" (called haptics) that secure the lens implant inside the lens capsule.
The primary difference between a conventional monofocal IOL and an accommodating IOL is the design of these haptics.