Hoya is the parent company of a group engaged in the manufacture and sale of optical glass and eyeglasses. Co.'s principal business segments are electro-optics, photonics, vision care, health care, crystal, and service. Co.'s principal products include photomasks and mask blanks for semiconductors, masks and color filters for crystal liquid display, glass disks for hard disk drives, and optical glasses; laser equipment, and optical communication related devices; eyeglass lens and frames and ophthalmic equipment; contact lenses and related accessories, intraocular lenses, and medical equipment; and crystal glass products such as tableware, interior items, and decorative objects.