Automatic refractor, lensmeter and keratometer utilizing Badal optics

A Badal system incorporated to an objective refractor for determining subjectively the power of an eye comprising in combination:

• a measuring station for a patient for placing the eye of said patient to an optical axis;
• means for emission of light along the optical axis into the human eye;
• means for imaging said light at the retina of said eye;
• a Badal lens positioned along said optical axis having said human eye at said measuring station positioned at the approximate focal length of said Badal lens;
• a detector positioned on said optical axis for receiving light passing light from said image on the retina through said eye and said Badal lens;
• a detector array for forming at said detector at least three sampling apertures for sampling light passing through said eye;
• detector array relay optics between said Badal lens and said detector array for defining a Badal space behind said Badal lens to permit the relay of light from discrete sampling apertures on said eye with the excursion of light between said sampling aperture at said eye and said detector responsive to the refraction of said eye;
• means for measuring the excursion of light emitted between discrete sampling apertures on the eye and the apertures of the detector array, this measuring means measuring that displacement normal to the axis of the Badal system whereby the excursion when measured gives a vector signature of lens power, which power may be conveniently converted to components of sphere, cylinder and axis or the equivalents thereof for the measurement of the eye.

A Badal system for determining the power of a lens inserted within an optical axis for test comprising in combination:

• means for emission of light along said optical axis through said lens from a first side of said lens;
• a Badal lens positioned along said optical axis on a second side of said lens, said Badal lens having said lens for test positioned at the approximate focal length of said Badal lens;
• a detector positioned on said optical axis at the second side of said lens for test for receiving light passing through said lens for test and said Badal lens;
• a detector array positioned on said optical axis for forming at said detector at least three sampling apertures for sampling light passing through said lens for test;
• detector array relay optics between said Badal lens and said detector array for defining a Badal space behind said Badal lens to permit the relay of light from discrete sampling apertures on said lens under test with the excursion of light between said sampling aperture at said lens for test and said detector responsive to the refraction at said lens under test;
• means for measuring the excursion of light emitted between the discrete sampling apertures at said lens for test and the detector array, this measuring means measuring that displacement normal to the axis of the Badal system whereby the excursion when measured gives a vector signature of lens power, which power may be conveniently converted to components of sphere, cylinder and axis or the equivalents thereof for the measurement of the lens for test.

A Badal system for determining the curvature of an eye under test comprising in combination:

• means for emission of light to the cornea of said human eye for reflection from said eye substantially along an optical axis;
• a Badal lens positioned along said optical axis having said cornea positioned at the approximate focal length of said Badal lens;
• a detector positioned on said optical axis for receiving light reflected from said cornea and said Badal lens;
• a detector array positioned on said optical axis for forming at said detector at least three sampling apertures for sampling light reflected from said cornea;
• detector array relay optics between said Badal lens and said detector array for defining a Badal space behind said Badal lens to permit the relay of light from discrete sampling apertures on said cornea with the excursion of light between said sampling aperture at said eye under test and said detector responsive to the reflection of said light from said cornea;
• means for measuring the excursion of light emitted between the discrete sampling apertures at the eye under test and the detector array, this measuring means measuring that displacement normal to the axis of the Badal system whereby the excursion when measured gives a vector signature of corneal curvature, which curvature may be conveniently converted to components of sphere, cylinder and axis or the equivalents thereof for the measurement of the curvature of said eye.