This is a synthetic lens that is implanted in the eye to replace the natural lens. lenses have different focal strengths (called dioptres) and the initial measurements taken of the eye, determine which size is best.
There are many different types and styles, usually they are Silicone or acrylic foldable lenses (which can vary in design)
They can be fixed or single focus (monofocal) or variable focus (bifocal or trifocal or accommodative).
Some lenses are specially made to deal with astigmatism as well as short or long sight and these are called 'toric' lenses.
Lenses are usually round in shape and are approximately 5-6mm across the optic or central portion. They are inserted into the eye via a tiny incision (less than 2mm).
To ensure they remain stable within the eye, they have stabilising arms called haptics.
In a one piece lens, the optic and haptic are as one, whilst they are joined together in the 3 piece version.
The intraocular lens is positioned behind the iris it is not usually visible from the front and would expect to remain in place for a life time.
A 3 piece multifocal
A single piece toric
A 3 piece monofocal
A multifocal surface