Abstract: Embodiments of the present invention relate to a multifocal lens having a mostly spherical power region and a progressive optical power region. Embodiments of the present invention provide for the proper alignment and positioning of each of these regions, the amount of optical power provided by each of the regions, the optical design of the progressive optical power region, and the size and shape of each of the regions. The combination of these design parameters allows for an optical design having less unwanted astigmatism and distortion as well as both a wider channel width and a shorter channel length compared to conventional PALs. Embodiments of the present invention may also provide a new, inventive far-intermediate distance zone and may further provide for increased vertical stability of vision within a zone of the lens.

Abstract: A film suitable for use in an ophthalmic system is provided. The film may selectively inhibit blue light within the wavelength range of 400 nm to 460 nm to reduce phototoxic light to the eye while maintaining photopic vision, and may be color balanced to allow for the system into which the film is incorporated to be perceived as colorless to a viewer observing and/or using the system. The system may have a photopic and scotopic luminous transmission of 85% or more and a phototoxicity ratio of less than 80%. When used in an ophthalmic system or other system disposed between an observer's eye and a light source, the film may reduce the flux of blue light to the internal structures of the eye while reducing or minimizing dilation of the pupil.

Abstract: A pressure relief bursting disc has a flange portion, a sloping portion interior of the flange portion and a dished portion interior of the sloping portion. The sloping portion has its wider end joined to the flange portion and slopes up from the flange portion in a first direction and is joined at its narrower end directly to the dished portion. The dished portion has its concave side facing in the first direction. In use pressure is applied to the concave side of the dished portion. The disc has a line of weakness, in the sloping portion. This shape achieves reliability of the burst strength, because the sloping portion buckles at the burst strength.

Abstract: A series of progressive ophthalmic lens elements, each lens element including a lens surface havingan upper viewing zone having a surface power to achieve a refracting power corresponding to distance vision;a lower viewing zone having a greater surface power than the upper viewing zone to achieve a refracting power corresponding to near vision;a corridor of relatively low surface astigmatism connecting the upper and lower zones, said corridor having a surface power varying from that of the upper viewing zone to that of the lower viewing zone;the progressive ophthalmic lens series includinga first set of lens elements having a base curve(s) suitable for use in providing a range of distance prescriptions for a first category of patient; anda second set of lens elements having a base curve(s) suitable for use in providing a range of distance prescriptions for a second category of patient;each lens element within a set differing in prescribed addition power and including a progressive design, in at least one of t

Abstract: A series of progressive ophthalmic lens elements, each lens element including a lens surface havingan upper viewing zone having a surface power to achieve a refracting power corresponding to distance vision;a lower viewing zone having a greater surface power than the upper viewing zone to achieve a refracting power corresponding to near vision;a corridor of relatively low surface astigmatism connecting the upper and lower zones, said corridor having a surface power varying from that of the upper viewing zone to that of the lower viewing zone;the progressive ophthalmic tens series includinga first set of lens elements having a base curve(s) suitable for use in providing a range of distance prescriptions for a first category of patient; anda second set of lens elements having a base curve(s) suitable for use in providing a range of distance prescriptions for a second category of patient; each lens element within a set differing in prescribed addition power and including a progressive design, in at least one of