Types of Intra-Ocular Lens Implants (IOLS) for cataract surgery
There are several options for choosing your customised lens implant:
Monofocal intra-ocular lens implants
This is the standard type of IOL which has a fixed focal distance. Usually this is set for distance where no glasses are generally required. However you will require reading glasses for near up work such as reading a newspaper or a menu. You may also need glasses for intermediate work such as using a computer. This is the standard IOL of choice available on the NHS. I use this type of lens in 100% of cases at Moorfields. I perform on average 40 cataract operations a month myself on the NHS.
Multifocal intra-ocular lens implants
A multifocal IOL consists of multiple zones that can focus light at various distances giving you a continuous range of vision without glasses. Many patients achieve excellent results with the ability to see distance and near without any glasses. Some patients do describe seeing rings or haloes around lights with these lenses which may impede some tasks performed in low light levels such as driving at night. Most patients can adapt to this side effect. Both eyes require a multifocal IOL implant for glasses free vision. If you have any other eye condition, this type of lens may not be best for you.
Toric intra-ocular lens implants
Astigmatism occurs when the shape of the cornea becomes irregular. If you have astigmatism, you can correct this irregularity with a toric intra-ocular lens implant. This correction allows good distance vision without glasses but you will still require reading glasses after your operation. This type of IOL can correct mild to moderate astigmatism. If you have high astigmatism, you may also require tiny relaxing cuts in the cornea called limbal relaxing incisions to further reduce the astigmatism.