Multifocal lenses can provide a far greater range of focus. Trifocal lenses target near, intermediate and distance vision. Four in 5 (80%) of patients will be spectacle-free with trifocal lenses; the remaining 1 in 5 (20%) may require reading glasses for some tasks. The potential downside of trifocal lenses is a comprise in the quality of distance vision as well as optical side effects (glare and haloes), particularly at night.
Extended Depth of Focus (EDoF) is the next generation technology in multifocal lens design. EDoF lenses let you see clearly at far and intermediate distances. They provide greater spectacle independence than monofocal lenses, while inducing less visual side effects compared to trifocal lenses. This balance of increased spectacle independence and less visual phenomena is particularly attractive to patients with an active lifestyle, who wish to be spectacle-free for most of their daily activities but are more sensitive to halos and glare. EDoF lenses are a particularly good option for patients who have had prior laser eye surgery.
Adjusting the focusing of EDoF lenses with the non-dominant eye slightly near-sighted (mini-monovision) can further improves reading vision. This means that with both eyes open, you have the advantages of both monofocal and multifocal IOLs: greater freedom from glasses and fewer side effects.
Try the simulator
A picture speaks a thousand words, or in this case, a simulator from lens manufacturer Zeiss. This useful tool will explain some of the differences and limitations of the various lens designs. Although the simulator discusses cataract, the same principles apply to RLE surgery with the same lenses being available for both types of surgery.
Click here to visit the simulator now.
