An imager that can measure the distance from each pixel to the point on the object that is in focus at the pixel is described here. This is accomplished by the use of short lightguide sections combined with each pixel light sensor. In the eye the rods and cones are the fiber like lightguide sections. The lens selects the object point who’s range is to be determined at the particular pixel. The lens reproduces the light pattern of the object point at the image point with the addition of a phase proportional to the distance from object point to image point. This is the input to the photoconducting lightguide. The light guide has contacts along its length. The total oscillating photo current is an exponential function of the product of the range times the loss coefficient, times the ratio of the group velocity of the lightguide to the velocity of light, times the range.
Kornreich, Philipp and Farell, Bart, "Single eye or camera with depth perception" (2012). Electrical Engineering and Computer Science - Technical Reports. 25.