What is an optical lens?

Keylenz is an optical  lens, not a magnifying glass.

A lens works by refraction, it bends light rays as they pass through it so they change direction. That means the rays seem to come from a point that's closer or further away from where they actually originate—and that's what makes objects seen through a lens seem either bigger, or smaller.

Unlike an optical lens, a magnifying glass can cause light rays to divert from their correct path, making a fuzzy image, or cause different colours to behave in different ways. This is why a Keylenz uses an optical lens, to enable a sharper clearer image. Keylenz's are also designed specifically for people who need reading glasses (for long-sighted rather than short-sighted people).