For the first 30 years of cataract surgery, monofocal lens implants were the only option available. They provide excellent vision but only at one distance. Patients who choose to have monofocal lens implants will be able to see well at a distance, but will still be required to have reading glasses after surgery. This type of lens will not correct intermediate or arms length vision, nor do these lens implants correct near vision and you will still have to depend on your reading glasses in about 70% of all cases.
When light enters the actual lens and it is bent to a specific focal point. The larger your prescription strength, the more the light is sharply increased. The light from these lenses is bent to focus specifically on the retina of the eye. The light can only be bent to one focus point at a time because the lens is monofocal.