Specialized coating for plastic lenses that helps retard scratching or crazing of lenses. Extremely beneficial in most cases for long term preservation of quality vision through your lenses. In the last several years, we've seen a tremendous improvement in the chemical engineering of scratch-resistance coatings.
Term meaning "crossed eyes." This happens when the muscles around the eye are not in proper alignment resulting in one eye crossing in, out, up, or down. This can lead to Amblyopia (reduced vision or "lazy eye") in the eye that is crossed. See Amblyopia this section, or click strabismus for more details.