Abstract: A progressive power multifocal lens by which a substantially good "broad field of view" can be obtained for an eyeglass wearer without increasing time and cost required to produce the prescribed surface thereof. This progressive power multifocal lens belongs to a group of progressive power multifocal lenses designed under a certain rule in such a manner that fundamental elements such as a far vision power measuring position F and a near vision power measuring position N thereof meet a common wearing object. Further, in the case of this lens, a surface refractive power (in units of diopters) at the far vision power measuring position F is employed as a base curve (Bi). Moreover, a difference in surface refractive power between the far vision power measuring position F and the near vision power measuring position N is employed as an addition Di (in units of diopters).

Abstract: An improved ophthalmic lens for presbyopia is disclosed in which the refractive power is progressively changed to provide a natural visual target arrangement. In the opthalmic lens, rotation of the head of a wearer for binocular lateral vision is taken into account to permit comfortable binocular lateral vision closer to vision with the naked eyes.

Abstract: When trifluoroethyl methacrylate, hexafluoroisopropyl methacrylate, pentafluoro-n-propyl methacrylate and/or pentafluoro-n-butyl methacrylate which are fluorine-containing monomers, are added to a conventional monomer mixture for producing a soft contact lens, the resulting soft contact lens has the same optical properties and elasticity as conventional soft contact lenses have, and is very superior to the conventional ones in resistance to deposit and in shape stability.

Abstract: A method for determining the optimum thickness of an ophthalmic lens comprises the steps of applying data indicative of the kind of a lens suitable for a spectacle wearer and the contents of a prescription as inputs to a computer, executing necessary computation by the computer according to a predetermined program on the basis of the various input data thereby drawing a map of an equi-thickness line group of the ophthalmic lens on the basis of the result of computation, and placing a spectacle frame at a predetermined position on the map of the equi-thickness line group to find out the outermost equi-thickness line within the extent of the frame.

Abstract: The oxygen-permeable hard contact lens of this invention produced by polymerizing in a composition composed of 30 to 50% by weight of an alkyl (meth)acrylate, 10 to 40% by weight of a fluorine-containing monomer, 10 to 35% by weight of a silicone (meth)acrylate, 5 to 15% by weight of an unsaturated carboxylic acid and 0.1 to 15% by weight of a di- or tri(meth)acrylate of a dihydric or higher hydric alcohol by raising a temperature continuously or stepwise from 40.degree. to 100.degree. C. and processing the resulting polymer into a lens shape by ordinary mechanical processing and polishing, is excellent in stain resistance, scratch resistance and hydrophilicity.

Abstract: A new subjective phorometer which can be a desk-type one in which all the measuring means are set on the desk plate and all the procedures for measuring vision data of eyes are carried out by control switches on the desk, and all the data measured are displayed digitally on a monitor, and printed out.The subjective phorometer comprises (1) the same measuring elements as conventional subjective phorometers, (2) a number of pulse motors, electro-magnetic clutches having a double-shafts mechanism, and direct current motors for driving the measuring elements and a number of sensors for detecting the zero position of the measuring elements, (3) a central processing unit and control switches for control driving of the pulse-motors, electro-magnetic clutches, and direct current motors, and (4) a monitor for displaying digitally the vision data measured, and (5) a printer for printing the data.

Abstract: A plastic lens of a stepped segment having an excellent surface hardness can be obtained at high molding efficiency from cast polymerization of a diethylene glycol bisallyl carbonate and specified acrylate(s) system further added with a specified diacrylate(s) and/or dimethacrylate(s).

Abstract: A lens having a high refractive index with a low dispersion produced by copolymerizing a polyfunctional allyl monomer with at least one monomer selected from the group represented by the general formula A: ##STR1## X: H, CH.sub.3, Cl Y: H, CH.sub.3, C.sub.2 H.sub.5, n-C.sub.3 H.sub.7, iso-C.sub.3 H.sub.7, OCH.sub.3, C.sub.6 H.sub.11, Cl, Br, CH.sub.2 Cl, CH.sub.2 Br, C.sub.6 H.sub.5, CH.sub.2 C.sub.6 H.sub.5, SCH.sub.3m=0, 1, 2n=0, 1, 2, 3, 4, 5.This lens is excellent in its transmittance, pencil hardness, impact resistance, dyeability, coating adhesion, solvent resistance, workability, etc.

Abstract: A high refractive lens of a terpolymer produced by the polymerization of ternary monomers comprising diethylene glycol bisallyl carbonate, triallylisocyanurate, and benzyl methacrylate. This lens is considerably improved in its physical properties necessary for lens such as superficial hardness, transmittance, and adhesion strength of glass film coated on the surface, as well as having a high refractive index.

Abstract: A calculating rule for obtaining ophthalmic values which are necessary for making eyeglasses, such as near-point distance, far-point distance, visual range, and addition, especially by which the eyeglasses-wearer can continue his work at the objective working distance with no asthenopia based on accommodation, from other ophthalmic values such as power of the ametropia, accommodation, etc., and for obtaining the resultant prism-diopter and base-direction of the prism for correcting heterophoria.

Abstract: Plastic eyeglass lenses and the like are marked with an identifying character or symbol by applying to the surface thereof or dissolving or comelting therein a flourescent dyestuff according to the disclosed method. When the proper amount of flourescent dyestuff is included the lens appears normal in sunlight but is characteristically marked in whole or in part under ultraviolet light depending on the area treated.

Abstract: The present invention relates to a copolymer for high refractive lens having a refractive index equal to or higher than 1.55, obtained by copolymerization of one or more of the first monomer component having the formula (I) ##STR1## wherein R.sub.1 signifies hydrogen atom or methyl radical, R.sub.2 signifies hydrogen atom or methyl radical, and m and n signify integers 0 to 4 in total, with one or more of the radically polymerizable second monomer component, homo-polymer of which has a refractive index equal to or higher than 1.55 and, if necessary, with the radically polymerizable third monomer component, the homo-polymer of which has a refractive index lower than 1.55 and to the lens prepared from said copolymer.

Abstract: An improved lensmeter comprising a conventional optical system and a novel displaying system. The displaying system includes a linear encoder producing two sets of pulse signals equivalent to the distance and direction of linear movement of the target and circuitry for converting the two sets of pulse signals to a dioptral number of digits, and displaying it. The dioptral number has a plus or minus sign and precision of 0.125 or 0.06 diopters. The displaying system also includes two circuits for displaying at the same time "the power of the sphere" (S) and "the power of the cylinder" (C) of an astigmatic lens respectively as a dioptral number of digits, a rotary encoder and circuitry for displaying "the direction of axis of the cylinder" (Ax) as an angular degree of digits, a (C) sign transposing circuit, and a cylinder form transposing circuit.

Abstract: A drilling machine comprising an article holding device and two drilling devices, being characterized that each drilling device has one drill turning in the same direction at a synchronized speed, each drill approaching to or separating from each other symmetrically to make a hole from both sides of a rigid and fragile article made of glass or ceramic e.g. lenses of spectacles at the same time, and that the hole is chamfered and further a groove for fixing the article to the frame is made on the article, as required.

Abstract: A soft contact lens having a water content of 20 to 45% and a tensile strength of at least 500 g/mm.sup.2 can be produced by pouring into a mold a composition comprising 70 to 90% by weight of an alkylene glycol monomethacrylate, 0 to 2% by weight of a polyfunctional monomer as a crosslinking agent, 0 to 5% by weight of an unsaturated carboxylic acid containing at least one carboxyl group in its molecule, 2 to 25% by weight of a methacrylic acid ester and 0 to 10% by weight of a vinyl monomer such as vinyl acetate, effecting polymerization of the composition, processing the resulting polymer into a lens, and then hydrating and swelling the lens thus obtained.

Abstract: Excellent and durable demisting property can be imparted to the surface of the transparent materials such as glass and plastics by coating onto the surface of said transparent materials a copolymer obtained by subjecting 2-hydroxyethyl methacrylate to solution polymerization and then graft-copolymerizing an allyl alcohol tribasic acid ester thereonto and then curing the copolymer by heating it. In this case, if an organo silicon nonionic surface active agent is added to said copolymer, more effective demisting property can be imparted to the surface of the transparent materials.

Abstract: The decrease in the impact resistance of the chemically pre-strengthened finished ophthalmic lens blanks due to the subsequent cutting and edging process can be prevented by coating the edge with at least one material selected from epoxy resins, alkyd resins, polyurethane resins, unsaturated polyester resins, acrylic resins or cyanoacrylates, polymerization of which can be completed by heating at a temperature of up to 200.degree. C, by single coating, overlap coating or multiple-layer coating, and then polymerizing the edge coating or coatings to form a polymeric film. Also, if a black pigment is added to any of the starting material compositions for said resins, internal reflections from the lens and the resulting myopic rings around the periphery of the lens can also be reduced.