A smart lens is a type of intraocular lens (IOL) technology, often referred to as a trifocal lens. These lenses are implanted to replace the natural lens during eye surgery, such as cataract surgery or refractive lens replacement.

Trifocal lenses are specially designed to meet the need for focusing at different distances in the eye. That is, they have multiple focusing zones to provide clear vision at both near and intermediate distances. This allows patients to see clearly both nearby objects and computer screens or books in the middle distance.

Advantages of trifocal lenses:

1. Multiple focusing: Provides clear vision at near, medium and far distances.
2. Independence: Can reduce or eliminate the need for glasses or contact lenses.
3. Better quality of life: Providing clear vision at various distances can make daily activities easier and more comfortable.