Test kits for assessing male fertility include a sample holder defining an object plane, a lens, and a two dimensional light sensor defining an image plane arranged along a common linear axis. The distance between the object plane and the image plane may be no more than 50 mm, and may be no more than 30 mm. A lens aperture may have an area of 1-10 mm2. The test kit may have a housing with a maximum linear dimension of no more than 100 mm. Processing circuitry may be provided that is configured to produce a sperm count and/or sperm motility measurements by processing image data from the two-dimensional light sensor.