Abstract: An objective phoropter utilizing an illuminated keratometric object projecting its illumination onto the subject's cornea, and imaging the reflection therefrom in an imaging camera. Image processing of these images is used to improve the focusing and centering of the cornea subject's eyes. Once the correctly focused position of the eyes is obtained relative to the keratometer object, an accurate longitudinal position of the eyes relative to the lens wheel assemblies can also be achieved. This results in more accurate prescription generation than in prior art systems where the eyes may not be accurately positioned relative to the lens wheels. Additionally, the lens combinations of the entire phoropter wheel can be calibrated using an artificial eye having adjustable levels of aberration. Each lens combination is adjusted to supposedly correct a selected aberration level, and any residual aberration measured represents the correction to be applied to that lens combination.

Abstract: Systems for performing sequential multiple function ophthalmic measurements using separate measurement instruments, by mechanical switching between the instruments. In prior art systems, the separate measurement instruments are stacked, and transfer between them is performed by means of a linear mechanical motion stage. The separate measurement instruments of the present application are mounted on a base which is rotatably pivoted around a joint at a location remote from the optical entry apertures of the instruments. The entrance apertures of the measurement instruments then traverse the eye being measured sequentially. A rotational motion around the pivoted joint is thus transformed into a linear motion at the eye of the subject, without the need for a linear motion stage. A Scheimpflug camera corneal thickness measurement is also described, in which the measurement head is tilted during the corneal scan such that the illuminating slit beam always impinges on the cornea normally.

Abstract: Systems for performing sequential multiple function ophthalmic measurements using separate measurement instruments, by mechanical switching between the instruments. In prior art systems, the separate measurement instruments are stacked, and transfer between them is performed by means of a linear mechanical motion stage. The separate measurement instruments of the present application are mounted on a base which is rotatably pivoted around a joint at a location remote from the optical entry apertures of the instruments. The entrance apertures of the measurement instruments then traverse the eye being measured sequentially. A rotational motion around the pivoted joint is thus transformed into a linear motion at the eye of the subject, without the need for a linear motion stage. A Scheimpflug camera corneal thickness measurement is also described, in which the measurement head is tilted during the corneal scan such that the illuminating slit beam always impinges on the cornea normally.