Spectacles are the most frequently requested and prescribed low vision device. They allow the user to have both hands free to hold material, and provide the widest field of view. Spectacle designs include base-in prism glasses for binocular or monocular use, in full or half frames, aspheric microscopic lenses, and doublet systems.
Prism glasses are designed to be used binocularly (but can be used monocularly) and are most frequently prescribed in half-eye frames to allow unobstructed distance vision. However, a full prism lens is helpful for patients who use eccentric viewing areas. Innovations in prismatic spectacle design allow specification of the patient's pupillary distance as well as additional base-in prism to facilitate comfort.
Aspheric microscopic lenses are available in full frames and half frames for monocular use by patients. Doublet lenses have the widest field of view for their power, with minimal peripheral aberration.
With all spectacles used in low vision, the working distance and lens weight are important considerations.