How to take close up eye photography?

Please Help, When I Take close up picture of an eye it does not focus With an DSLR. How Can I Take It Close Please, Because I Wanna Upload It And Edit… Nikon d5100 flash sb-700

Put it on Macro mode, or get macro lenses and place it near the eye. Do not use flash, unless you want to be blind for a day.

Without knowing what lenses you have access to, it will be hard to advise you. Most have a 18-55mm or something similar in a zoom as a kit lens. Your best bet is to use the shortest focal length lens or setting, assuming you don't have a macro lens. Depending on focal length, you should find the closest focus on the focus ring is around a foot at 15-20mm range. Set the person, assuming this isn't a self portraiture thing, in a comfortable chair. Arrange a tripod at the right spot and set aperture to about f/11 with the camera on aperture priority mode or manual mode. Focus and determine exposure, then shoot making sure to turn off anti-shake mode.

You should get a fairly good picture of an eye that is reasonably large in the shot.