Contact lens arrangement for optically examining an eye and treating it by light irradiation

Claim 1

A contact lens arrangement for optically examining an eye and treating it with an incident light beam, the beam traveling a distance e inside the lens arrangement between an entry surface and an exit surface which is applied to the eye, and the eye producing for said beam an astigmatism defined by a sagittal focal distance S and a tangential focal distance T, the lens arrangement comprising: a principal element for focusing said beam onto a working point on the retina inside the eye, said principal element having a refractive index n and being provided with a plane entry surface and an exit surface forming said lens arrangement exit surface, the axis of said beam being displaced from the optical axis of said principal element and perpendicular to said plane entry surface thereof; and a compensating element having a refractive index n and a plane exit surface which is coupled with the plane entry surface of the principal element, said compensating element being provided with an entry surface forming said lens arrangement entry surface such that a plane tangent to said entry surface of the compensating element, at the point where the axis of said beam strikes the lens arrangement, is inclined with respect to the plane entry surface of the principal element by an angle which is selected on the basis of e, S, T and n so as to produce for said beam an astigmatism opposite to that of the eye.