This paper presents an enhancement method based on human visual characterstics (HVC) for medical images. In medical field images suffer from poor contrast and sometimes information is hidden in dark areas, due to this we are not able to extract information from them. We are presenting a method which takes care of these factors. According to HVC, human eyes are more sensitive towards plenty of details or great changings and less sensitive to smooth regions. So we divide the images in smooth area and detail area by discrete wavelet transform (DWT), and then use different processing methods for these areas according to HVC. Moreover, our experimental results validate that the proposed method performs better than conventional histrogram equalization method. © 2010 Copyright SPIE - The International Society for Optical Engineering.