This invention relates to a wide angle objective for the visual and photographic examination of the fundus of the eye, in which disturbing light reflections are suppressed by light-arresting black points.
Objectives having a field of view of about 30 degrees are known for the examination of the retina of the eye. An object of the present invention is to provide an objective for the examination of the retina which permits a substantially larger angle of view than 30 degrees, preferably up to about 50 degrees.
This object is achieved, in accordance with the invention, by designing the individual lenses (lens elements) which make up the objective with such dimensions that one of the two surfaces of each lens provides the refractive power and the other surface of the same lens is concentric with the pupil locus produced by the surface which provides the refractive power. The surface providing the refractive power may be either spherical or aspherical.
Black points which suppress the reflections are advantageously provided in the objective at the locus of the ghost images produced.
The advantages obtained with this invention include especially the fact that large angles of view, for instance an angle of 50 degrees, are obtained with a design which is easy to carry out in practice.