An ultra wide-angle large-aperture lens sequentially comprises at least three parts from an object side to an image side: a first lens group G1, a second lens group G2, and a third lens group G3; when an object moves closer from infinity, the first lens group G1 is fixed, the second lens group G2 and the third lens group G3 move, to implement an ultra wide-angle microlens which is in focus and meets the following conditional expressions: 1.2(|F12|+S)/LB2.5(1); 0.8(|F12|+S)/(tan LB)1.3(2).

An ultra wide-angle large-aperture lens sequentially comprises at least three parts from an object side to an image side: a first lens group G1, a second lens group G2, and a third lens group G3; when an object moves closer from infinity, the first lens group G1 is fixed, the second lens group G2 and the third lens group G3 move, to implement an ultra wide-angle microlens which is in focus and meets the following conditional expressions: 1.2(|F12|+S)/LB2.5(1); 0.8(|F12|+S)/(tan LB)1.3(2).

The zoom lens consists of, in order from an object side: a first lens group that has a positive refractive power; a second lens group that has a positive refractive power; a third lens group that has a negative refractive power; a fourth lens group; and a fifth lens group that has a positive refractive power. The first lens group and the fifth lens group remain stationary with respect to an image plane during zooming. The second lens group, the third lens group, and the fourth lens group are moved by changing distances between the lens groups and adjacent groups in a direction of an optical axis during zooming, and are positioned to be closer to the image side at a telephoto end than at a wide-angle end. Conditional Expression (1) is satisfied.

0.8<pr1/f1<2.6(1)

The zoom lens consists of, in order from an object side: a first lens group that has a positive refractive power; a second lens group that has a positive refractive power; a third lens group that has a negative refractive power; a fourth lens group that has a positive refractive power; and a fifth lens group that has a positive refractive power. The first lens group and the fifth lens group remain stationary with respect to an image plane during zooming. The second lens group, the third lens group, and the fourth lens group are moved by changing distances between the lens groups and adjacent groups in a direction of an optical axis during zooming, and are positioned to be closer to the image side at a telephoto end than at a wide-angle end. A stop is provided between the fourth lens group and the fifth lens group. In addition, Conditional Expression (1) is satisfied.

0.1<fw/f4<0.5(1)

A varifocal lens includes a first phase plate and a second phase plate which are rotatable relative to each other about an optical axis. The first phase plate includes a plurality of first phase conversion elements, the second phase plate includes a plurality of second phase conversion elements, and the plurality of first phase conversion elements and the plurality of second phase conversion elements are arranged so that light transmitted through the first phase plate and the second phase plate is focused on different positions on the optical axis depending on a relative rotational displacement between the first phase plate and the second phase plate.

A varifocal lens includes a first phase plate and a second phase plate which are rotatable relative to each other about an optical axis. The first phase plate includes a plurality of first phase conversion elements, the second phase plate includes a plurality of second phase conversion elements, and the plurality of first phase conversion elements and the plurality of second phase conversion elements are arranged so that light transmitted through the first phase plate and the second phase plate is focused on different positions on the optical axis depending on a relative rotational displacement between the first phase plate and the second phase plate.

Provided is a zoom lens, including, in order from object side: a positive first unit; a negative second unit; a third unit having a positive or positive refractive power; and a rear group including at least one unit, in which: the first unit is not moved for zooming, and intervals between adjacent units are changed during zooming; the first unit includes three lenses, and the second unit includes three lenses; at least two lens surfaces, among lens surfaces of lenses included in the second unit except for a lens arranged closest to the object side, have aspherical shapes; and focal lengths of the zoom lens at a wide angle end and at a telephoto end, movement amounts of the second and third units during zooming from the wide angle end to the telephoto end are appropriately set.

Provided is a zoom lens, including, in order from object side: a positive first unit; a negative second unit; a third unit having a positive or positive refractive power; and a rear group including at least one unit, in which: the first unit is not moved for zooming, and intervals between adjacent units are changed during zooming; the first unit includes three lenses, and the second unit includes three lenses; at least two lens surfaces, among lens surfaces of lenses included in the second unit except for a lens arranged closest to the object side, have aspherical shapes; and focal lengths of the zoom lens at a wide angle end and at a telephoto end, movement amounts of the second and third units during zooming from the wide angle end to the telephoto end are appropriately set.

An ophthalmic surgical microscope includes a beam coupler positioned along an optical path of the surgical microscope between a first eyepiece and magnifying/focusing optics, the beam coupler operable to direct the OCT imaging beam along a first portion of the optical path of the surgical microscope between the beam coupler and a patient's eye (an OCT image being generated based on a reflected portion of the OCT imaging beam). The surgical microscope additionally includes a real-time data projection unit operable to project the OCT image generated by the OCT system and a beam splitter positioned along the optical path of the surgical microscope between a second eyepiece and the magnifying/focusing optics. The beam splitter is operable to direct the projected OCT image along a second portion of the optical path of the surgical microscope between the beam splitter and the second eyepiece such that the projected OCT image is viewable through the second eyepiece.

An ophthalmic surgical microscope includes a beam coupler positioned along an optical path of the surgical microscope between a first eyepiece and magnifying/focusing optics, the beam coupler operable to direct the OCT imaging beam along a first portion of the optical path of the surgical microscope between the beam coupler and a patient's eye (an OCT image being generated based on a reflected portion of the OCT imaging beam). The surgical microscope additionally includes a real-time data projection unit operable to project the OCT image generated by the OCT system and a beam splitter positioned along the optical path of the surgical microscope between a second eyepiece and the magnifying/focusing optics. The beam splitter is operable to direct the projected OCT image along a second portion of the optical path of the surgical microscope between the beam splitter and the second eyepiece such that the projected OCT image is viewable through the second eyepiece.