Abstract

An ocular biometer utilizing a light emitting source (7) and corresponding optics to illuminate areas of the eye in order to analyze the wavefront of the reflected light. Aperture sharing elements, such as "hot mirrors" (4) are used to allow the eyes (1) to view the world, as the ocular biometer measures various characteristics of the eye such as the refractive (i.e., accommodative) state, the gaze angle and the pupil diameter at any instant of time and continuously. Optical wavefront conditioning and wavefront sensing techniques are used to determine the refractive power of the eye and the instantaneous accommodative state. Reflected light is projected through a reticle (26) or plurality of reticles (26, 28). Spatial characteristics of the resulting shadow pattern uniquely determine the characteristics of the eye. These shadow patterns can be measured directly or by causing a modulation of the lines with a second identical reticle placed appropriately between the first and the imaging plane. The bright pupil and a Purkinje image may be used to compute the gaze angle (or, line-of-sight). A bright pupil on a dark background wil provide the pupil diameter measurement. The ocular biometer can be configured in a binocular manner so that both eyes can be investigated simultaneously for strabismus, stereopsis and convergence measurements. The depth of modulation of the modulated shadow pattern provides an indication of the acuity of the ocular media and the retinal surface thus providing a means for screening such medical anomalies as diabetic retinopathy, glaucoma and cataracts.