Intraocular lenses
Intraocular lens (IOL) is a lens implanted in the eye as part of a treatment for cataracts or myopia. If the natural lens is left in the eye, the IOL is known as phasic, otherwise it is a pseudophakic, or false lens. Such a lens is typically implanted during cataract surgery, after the eye’s cloudy natural lens (cataract) has been removed. The pseudophakic IOL provides the same light-focusing function as the natural crystalline lens. The phakic type of IOL is placed over the existing natural lens and is used in refractive surgery to change the eye’s optical power as a treatment for myopia (nearsightedness).[1] This is an alternative to LASIK.
IOLs usually consist of a small plastic lens with plastic side struts, called haptics, to hold the lens in place in the capsular bag inside the eye.[2] IOLs were conventionally made of an inflexible material (PMMA), although this has largely been superseded by the use of flexible materials, such as silicone. Most IOLs fitted today are fixed monofocal lenses matched to distance vision. However, other types are available, such as a multifocal intraocular lens that provide multiple-focused vision at far and reading distance, and adaptive IOLs that provide limited visual accommodation. Multifocal IOLs can further be, Trifocal IOLs or extended depth of focus (EDOF) lenses.