As simple as TruFocals are to use, their technology is very sophisticated.
Each "lens" is actually a set of two lenses, one flexible and one firm. The flexible lens (near the eye) has a transparent distensible membrane attached to a clear rigid surface. The pocket between them holds a small quantity of crystal clear fluid. As you move the slider on the bridge, it pushes the fluid and alters the shape of the flexible lens. Changing the shape changes the correction. This mimics the way the lenses in your eyes used to perform when you were younger.
This allows you to choose the exact correction that works best for you at any distance and under any lighting conditions. The result: clear, undistorted vision over a wide field of view: no zones, no lines.
[Not to scale; blue denotes optically clear surfaces; yellow denotes optically clear liquid.]
“TruFocals provide a much larger in focus lens area than other correction modalities, thereby allowing natural eye movement instead of aiming the eye utilizing cramping head and neck motion.”- DF
