It has never been easier to have cataracts corrected with surgery, and cataract patients have a range of options when it comes to how they want to be treated. One of the most important choices patients must make when considering cataract surgery is which type of intraocular lenses (IOLs) to have inserted—these artificial lenses are inserted into the eyes to replace the cloudy, damaged natural lenses that cause cataracts, and there are many different types available. These lenses each have different properties, so do some research and consult with your optometrist and other medical professionals before you decide which kind of lens best fits your needs.
Monofocal IOLs
These lenses are generally considered the standard for cataract-correcting lenses, and consist of a simple curved lens which provides clear, effective vision at a distance of your choice. Depending on your everyday lifestyle, this distance can be set to give you close, intermediate or long-distance focus, minimising the need for glasses or contact lenses. The simplicity of these lenses means they're among the cheapest lens options, and they are relatively simple to have fitted during surgery. However, they can be very limiting for people who need to focus on various distances frequently, such as professional drivers.
Toric monofocal IOLs
A refinement of the basic monofocal IOL, these lenses are donut-shaped (the shape is more properly known as a torus) to provide different light refraction characteristics to basic curved lenses. This special shape allows toric lenses to be used to correct astigmatism as well as cataracts. and provides the same excellent vision at set distances as standard monofocal lenses. However, they tend to be more expensive, and may not be necessary for cataract patients with minor or no astigmatism.
Multifocal IOLs
As you've probably already guessed, these lenses provide clear vision over a range of differences, using different magnifications in different parts of the lens to provide the most versatile vision possible. Using these lenses can dramatically reduce your need for reading glasses and other corrective devices, and tend to be particularly useful for correcting short-distance vision. However, the varying magnifications of the lens can cause minor problems with image interference, glare and blurriness, and can also affect your peripheral vision. Multifocal lenses also tend to be the most expensive lens option commonly available.
Accommodating IOLs
An alternative to the standard multifocal IOL, accommodating lenses are fitted with a number of flexible struts. These struts serve to hold the lens in its proper position, while flexing slightly when the eye moves—this changes the shape and angle of the lens, allowing it to adjust to different focal lengths as the eye moves to focus on different distances and objects. They tend not to be as versatile as true multifocal lenses for vision over all distances, and excel at providing long-distance vision rather than close viewing.
