Apparatus for use with an operating microscope employed in observing the cornea of the human eye, for example in connection with cornea transplant operations. A plexiglass tube surrounds the objective of the microscope and is fed with light from a suitable source, so that an image of the circular illuminated lower end of the plexiglass tube is reflected by the cornea of the patient back into the microscope and is observed by the person using the microscope. The character and extent of distortion of the reflected image is an indication of the corneal astigmatism. The eyepiece of the microscope is provided with a reticle in connection with which the reflected image is observed. In one form of the invention, the recticle has diametrical crossed lines and concentric circular lines. In other form of the invention the recticle has a diametrically extending linear scale, and is used in connection with an eyepiece attachment having means for rotating the recticle to align the linear scale with any desired axis of the reflected image and micrometer means for moving a pointer to measure the length of the reflected image along such axis.
A hand-held keratoscope designed to project a bright circular ring on the cornea having a circular glass ring attached to a handle by a retainer ring with the circular glass ring having a flat polished top surface and a frosted inward sloping bottom surface.
An assembly is provided for the direct measurement of a vertical intensity profile through a plane of focus of a confocal microscope, a determination of a depth of the confocal plane and a maximum intensity of the intensity profile. The assembly includes a transparent substrate in which is embedded a scale having a graduated length, wherein the scale is inclined relative to a local portion of an illuminating beam on an illuminating path of the confocal microscope. The graduated scale is configured to be illuminated with an intensity corresponding to the position within the plane of focus along the axis of the illuminating beam. The inclination of the scale and the path of the illuminating beam are at a predetermined angle. The graduated scale can be fluorescently dyed to illuminate with an absorption frequency relevant to a light source or illuminating beam of the confocal microscope. An algorithm employing trigonometric functions and calculating the confocal plane depth of the specimen is disclosed.
A protraction device for a measuring microscope comprises a reticle aligned on an optical path of the microscope at an intermediate image plane thereof and adapted for rotation about a central axis, and an angle encoder operably coupled to the reticle such that when the angle encoder is rotated about its rotational axis, a corresponding rotation is produced in the reticle. The angle encoder provides a signal representative of an angular displacement of the reticle which is delivered to a printer, digital display, or the like.
An assembly is provided for the direct measurement of a vertical intensity profile through a plane of focus along an illuminating beam, a determination of a depth of the focal plane and a maximum intensity of the intensity profile. The assembly includes a plurality of focusing indicia fixed relative to a substrate, the focusing indicia being distributed at different locations along the illuminating beam. The focusing indicia are configured to be illuminated with an intensity corresponding to the position relative to the plane of focus along the axis of the illuminating beam. The location of the respective focusing indicia can be predetermined, such as along a given scale at a given inclination of the scale and the path of the illuminating beam, or not initially known and subsequently determined.
In an optical beam-doubling and image-rotating device, beam splitting means are provided for creating a first and a second image of an optical target in conjunction with means for rotating the light-ray family associated with the second image yielding a second image which has been rotated axially through a defined angle with respect to the first image, in further conjunction with additional beam splitting means so disposed as to combine the first and rotated second images so that they may be visually compared under the conditions of a specifically defined relative angular displacement. The disclosed use is in measuring the sphericity of the cornea of the eye during ophthalmic surgery.
