Glaucoma is a type of eye disease affecting the optic nerve, which is important for good vision safety. The effect is usually an abnormally high pressure of the eye.In this study, an efficient method for glaucoma diagnosis using Histogram Matching (HM) algorithm and color space is presented. Initially, the red, green and blue color components are separated. Finally, HM is used for glaucoma diagnosis. The experimental results and discussion shows the performance of the proposed system.