Presbyopia corneal implants

A doctor recently told me about a clinical trial on AcuFocus corneal implants for presbyopia. It is a very simple dark ring that reduces the aperture of the pupil to create the "pinhole effect". I understand how this works but have two questions. Why would this technology not apply to a contact lens that could accomplish the same thing? What keeps the vision from being too dim from the reduced light like the effect of pinhole glasses.

[Sandy Feldman, MD, MS]

Dear Buttercup109,

These are questions that are being answered in the clinical studies.  The membrane is a very thin material and differs from a contact lens.  This approach may not work as a contact lens since the lens moves as one blinks.

Dr. Feldman

Sandy T. Feldman, M.D., M.S.
ClearView Eye and Laser Medical Center
San Diego, California