http://www.nikonchat.com/nikon-viewfinder-accessories/

The use of glasses with the D-80? accessory?
I wear glasses and can not wear contact lenses unfortunately. I have a Nikon D-80 and I think more and more more difficult to look through the viewfinder with my glasses.Is Did any additional viewer could use to help me? Thanks
There are adapters that you can put on the display (eg rubber cylinders) that will make viewing with glasses a little better. The other option is to use the viewfinder diopter adjustment for is such that you can use your camera without his glasses. The D80 should have a small wheel next to the viewfinder. This is the diopter adjustment. Point your camera at something and press the shutter slightly for the picture in focus. Then turn the diopter adjustment wheel (probably pretty hard so they could be difficult turn) until the middle of the image is in focus for you. This may be easier on a tripod where you can keep the camera steady after focusing the lens. If the diopter is not adjustable enough for his eyes are mirrors you can buy that have a higher setting.
OUTEX in Action Higher Resolution.m4v