A battery-powered ophthalmic device designed to test and train vision for conditions where decreased visual acuity may be due to unequal vision in the eyes (e.g., presbyopia). It is in the form of spectacles with lenses that can independently be made opaque electronically, so that the stronger eye is occluded to promote use of the weaker eye. It is intended to be used for short intervals (e.g., 15 – 30 minutes), typically at home, and is normally available [non-prescription] over-the-counter (OTC). This is a reusable device.