TheNikon DK-17C -2.0 Correction Eyepieceoffers dioptre correction designed to counteract short-sightedness. Soft and comfortable, the rubber outer surface provides an ergonomic and non-irritating zone where the eyepiece sits around the eye, framing subject composition for a selected view through the cameras viewfinder. The Nikon DK-17C -2.0 Correction Eyepiece dioptre compensates for relatively near sight, pushing the very edge of viewing out into the distance, while also blocking unwanted, and potentially distracting, light that might enter the viewfinder at low angles. The DK-17C -2.0 Correction Eyepiece fits to the viewfinder easily and securely. It is compatible with some Nikon cameras with the Nikon DK-17C -2.0 Correction Eyepiece.To determine which Nikon diopter is best suited for you, it is recommended to consult your eye care professional. Nikon SLR and DSLR cameras without built-in adjustable eyepiece correction have a base diopter value of -1. -1 is considered the optimum starting point for the majority of SLR or DSLR users with normal vision. No combination of that -1 base value and a diopter’s value is required to arrive at the final desired value. In other words, if you require a diopter of +2, simply add a +2 diopter to your camera.Compatible CamerasD5 D4S D4 D3X D3S D3 D2H D2X D2Xs D2Hs D850 D810A D810 D800E D800 Df D700 D500