Abstract: A progressive power lens pair is provided with an object-side surface and an eyeball-side surface of the right-eye lens and an object-side surface and an eyeball-side surface of the left-eye lens which are set by ensuring that ADDR1?ADDR2 and ADDL1?ADDL2 take values different from each other, when prescribed additional power for the right-eye lens and prescribed additional power for the left-eye lens are equal to each other; and prescription information for the progressive power lens pair indicates: that spherical power SR at the right-eye lens and spherical power SL at the left-eye lens are different from each other, that astigmatic power CR at the right-eye lens and astigmatic power CL at the left-eye lens are different from each other, or that an astigmatism axis angle AxR corresponding to the right-eye lens and an astigmatism axis angle AxL corresponding to the left-eye lens are different from each other.

Abstract: A subject matter is to provide an efficient method for designing a progressive refraction lens in consideration of not only its optical performance but also its appearance performance. The method for designing the progressive refraction lens includes a step (S030) for determining addition power of an entire lens that is a summation of addition power of a front surface and that of a back surface and a step (S040) for determining the addition power of the front surface. The method for designing the progressive refraction lens is characterized in determining to make the addition power of the front surface not less than 0 but smaller than that of the entire lens in the case that the appearance performance is considered to be more important than the optical performance while determining to make the addition power of the front surface larger than that of the entire lens in the case that the optical performance is considered to be more important than the appearance performance.

Abstract: A subject matter is to provide an efficient method for designing a progressive refraction lens in consideration of not only its optical performance but also its appearance performance. The method for designing the progressive refraction lens includes a step (S030) for determining addition power of an entire lens that is a summation of addition power of a front surface and that of a back surface and a step (S040) for determining the addition power of the front surface. The method for designing the progressive refraction lens is characterized in determining to make the addition power of the front surface not less than 0 but smaller than that of the entire lens in the case that the appearance performance is considered to be more important than the optical performance while determining to make the addition power of the front surface larger than that of the entire lens in the case that the optical performance is considered to be more important than the appearance performance.

Abstract: 1 indicates the rotating point of the eyeball, 2 indicates the first eye position, 3 indicates the second eye position, and 4 indicates the third eye position. The lines indicated by thick lines at the respective eye positions are the horizontal meridian and vertical meridian (principal meridian) of the cornea. As is seen from the figure, the directions of the horizontal meridian and vertical meridian of the cornea at the third eye position 4, in particular, do not coincide with the directions of the horizontal meridian and vertical meridian at the first eye position 1. In the present means, in order to perform aberration correction of the ophthalmic lens not only in the first eye position and second eye position but also in the third eye position under conditions that are suited to the prescription of the user and conditions of use, the prescription surface is made aspherical while taking into account the astigmatic axis of the eye at arbitrary eye positions in accordance with the laws of Donders-Listing.

Abstract: 1 indicates the rotating point of the eyeball, 2 indicates the first eye position, 3 indicates the second eye position, and 4 indicates the third eye position. The lines indicated by thick lines at the respective eye positions are the horizontal meridian and vertical meridian (principal meridian) of the cornea. As is seen from the figure, the directions of the horizontal meridian and vertical meridian of the cornea at the third eye position 4, in particular, do not coincide with the directions of the horizontal meridian and vertical meridian at the first eye position 1. In the present means, in order to perform aberration correction of the ophthalmic lens not only in the first eye position and second eye position but also in the third eye position under conditions that are suited to the prescription of the user and conditions of use, the prescription surface is made aspherical while taking into account the astigmatic axis of the eye at arbitrary eye positions in accordance with the laws of Donders-Listing.

Abstract: A series of progressive power multifocal lenses having a plurality of base curves which are designed to have substantially the same basic lens specifications and substantially the same optical characteristics in the worn state with respect to all of the base curves, so as to have an excellent optical performance in the worn state. The progressive power multifocal lens secures a wide clear vision range with a smaller amount of astigmatism in the far portion and a smaller amount of blur of the image due to a dioptric power error.

Abstract: A progressive-power multifocal lens whose far-vision portion dioptric power is minus, which has, along a principal meridian curve, a far-vision correction portion, a near-vision correction portion, a progressive-power portion between the far-vision correction portion and the near-vision correction portion.

Abstract: An image stabilizing optical system having both a simple configuration and high optical performance can be used as an optical system for observation such as a telescope or a binocular. The image stabilizing optical system consists of a first lens group having positive refractive power, a second lens group having negative refractive power and disposed movably in a direction substantially perpendicular to the optical axis, and an erecting prism system, all of which are arranged in order from an object. The optical system includes an objective lens system for forming an erected image at a position on the eye-side of the erecting prism system and an eyepiece lens system having positive refractive power as a whole and magnifying the erected image so as to allow the magnified erected image to be observed. The first lens group includes at least one positive lens and one negative lens.

Abstract: A progressive-power multifocal lens whose far-vision portion dioptric power is minus, which has, along a principal meridian curve, a far-vision correction portion, a near-vision correction portion, a progressive-power portion between the far-vision correction portion and the near-vision correction portion.

Abstract: A series of progressive power multifocal lenses having a plurality of base curves which are designed to have substantially the same basic lens specifications and substantially the same optical characteristics in the worn state with respect to all of the base curves, so as to have an excellent optical performance in the worn state. The progressive power multifocal lens secures a wide clear vision range with a smaller amount of astigmatism in the far portion and a smaller amount of blur of the image due to a dioptric power error.

Abstract: A progressive multifocal lens is provided with a near part N, a defined vision part F, and an intermediate part P along the main meridian curve MM'. The near center B of the lens is separated from near eyepoint E by a distance of substantially 2 mm to 8 mm in the lower part along the main meridian curve. The refractive power K.sub.E at the near eyepoint, refractive power K.sub.A at the defined center A, and refractive power K.sub.B at the near center B satisfy the condition:0.6<(K.sub.E -K.sub.A)/(K.sub.B -K.sub.A)<0.9.

Abstract: An eyepiece lens suitable for use in microscopes, binoculars, and the like is disclosed. The eyepiece lens provides a large eye relief of more than 80 percent of the focal length of the eyepiece lens in an apparent field of view of more than 60 degrees, preferably more than 70 degrees, while favorably correcting various aberrations such as distortion up to the perimeter of the apparent field of view of the eyepiece lens. The eyepiece lens is disposed on the eye side of a real image plane of an objective lens with which the eyepiece lens is used, and comprises, in order from the objective side, a first cemented lens L.sub.1, preferably a doublet, a second cemented lens L.sub.2, preferably a doublet, a first positive lens element L.sub.3, and a second positive lens element L.sub.4. The eyepiece lens preferably satisfies a number of quantitative conditions.

Abstract: An eyepiece lens is disclosed that corrects aberrations over a wide apparent field of view, and has a short overall length and sufficiently long eye relief (typically at least 150% of overall focal length F). The eyepiece lens comprises, in order from the objective lens side, first and second lens groups having negative and positive refractive power, respectively, with a field stop situated therebetween. The first lens group comprises a cemented negative lens including two lens elements cemented together. The second lens group comprises, in order from the objective lens side, a positive meniscus lens element having a concave surface oriented objectivewise; a cemented lens comprising two lens elements cemented together and in which the most objectivewise lens surface is a concave surface oriented objectivewise; and a lens subgroup having positive refractive power and comprising a positive meniscus lens element having a concave surface oriented eyewise. The eyepiece lens satisfies at least the conditions: -4.5.