Accommodating IOLs reduce the need for reading glasses by increasing the magnifying power of the eye in response to focusing effort (a process called accommodation).
But these lenses work differently than the eye's natural lens.
Accommodating IOLs are an advanced type of intraocular lens implant designed to correct presbyopia as well as nearsightedness and farsightedness.
Currently available accommodating IOLs do not correct astigmatism, but several options exist for the correction of astigmatism after accommodative IOL surgery, including standard LASIK, custom LASIK (also called wavefront LASIK), PRK, and other laser vision correction procedures.
Another option is a non-laser procedure called limbal relaxing incisions.
Accommodating IOLs can be used in refractive cataract surgery for cataract patients or they can be used in refractive lens exchange (RLE) for people who don't have cataracts, but want lens-based vision correction surgery to reduce the need for reading glasses.
Contraction and relaxation of the ciliary muscle changes the tension in the zonules, which in turn changes the shape of the lens to provide the correct focusing power for seeing objects at all distances.
To see clearly far away, the focusing muscle relaxes and the lens becomes flatter.
To see clearly up close, the ciliary muscle contracts and the lens becomes more curved.
Because the central optical portion of an accommodating IOLs typically is less flexible than the eye's natural lens, these intraocular lenses must work in a different way.
Instead of changing shape, an accommodative IOL moves slightly forward within the eye in response to focusing effort.
This forward movement is made possible by the "legs" (or haptics) of the accommodating IOLs, which are flexible.
When an accommodating IOL is implanted in the eye, the haptics of the IOL are positioned within the capsule of the eye's natural lens after the lens has been removed.