The prevalence of cataracts, a condition where the lens inside the eyes becomes cloudy, is relatively high amongst senior American citizens. According to the National Eye Institution (NEI), approximately 68.3% of Americans over the age of 80 had cataracts in 2010. Fortunately, modern day cataract surgery is generally quite safe and effective, as the procedure produces excellent outcomes and can almost completely restore one's visual acuity. Once the clouded lenses are removed, the surgeon will replace it with an artificial intraocular lens. Patients scheduled for cataract surgery should familiarize themselves with the 3 most common types of intraocular lenses recommended. This will allow them to make a more informed decision.

The Simplicity of Monofocal Intraocular Lenses

Monofocal intraocular lenses are generally recommended for those who have cataracts in both of their eyes. These types of lenses offer visual acuity for only one distance whether it be near focus, mid-distance focus or distant focus. The focus of the lens will not change after the surgery. As a result, this typically means that the patient may have to wear glasses. For example, patients who chose to implant near focus lenses are generally able to read perfectly well; however, they may need glasses to clearly see distant objects. 

Those who would like to reduce usage of eyeglasses as much as possible may want to consider trying out a strategy known as monovision. This basically involves implanting a distant focus lens in one eye and a near focus lens in the other. Ideally, the brain will process the visual information it receives from both eyes. Although this strategy has been known to be effective, patients do typically require longer recovery times in order to adjust to the contrasting visual information provided by each eye. 

The Convenience of Multifocal Intraocular Lenses

Multifocal intraocular lenses are typically chosen by patients who place a strong importance on convenience. Multifocal intraocular lenses are different from monofocal intraocular lenses in the sense that they do not restrict the patients' vision to one distance only. These types of lenses have a series of different focal zones or rings integrated straight into the design. Depending on how the light is refracted onto the surface of the lenses, the patients can focus their vision to various distances.

Studies have shown that patients who have opted for multifocal intraocular lenses typically enjoyed an increase in the quality of unaided vision, with most patients claiming that they either "never" or "only now and then" wear spectacles. Although multifocal intraocular lenses allow patients to forgo eyeglasses more often, patients are at a higher risk for experiencing side effects like distorted vision or halos.

The Specificity of Toric Lenses

Patients with astigmatism are generally limited to only toric lenses. These lenses are similar to monofocal intraocular lenses; however, they have astigmatism correction built into the design. Once again, patients are able to choose between different focal points. Generally speaking, patients with astigmatism should not attempt implanting different focal lenses to each eye.

Although monovision may not be an effective strategy, patients with astigmatism may want to also undergo surgery for limbal relaxing incisions along with their cataract surgery. Limbal relaxing incisions will help to shape the cornea for better focus and visual acuity.

Conclusion

Understanding the type of intraocular lenses that will be implanted during the cataract surgery is important. Depending on the type of lenses that are implanted, patients can expect different types of results. It's important to understand the unique benefits and drawbacks that are provided by each type of lens in order to determine what may work best based on one's lifestyle and needs.