Measuring Marginal Reflex Distance-1 (MRD-1) is an important clinical tool used to assess the position of the eyelid margin relative to the cornea. Traditionally, this has been done manually by ...

Defining a DSLR A cut away view of Nikon’s D800 camera. Image used with permission by copyright holder In the most literal sense, a DSLR camera is a digital single-lens reflex camera.