You must set up a good work environment and profile your monitor so that you can accurately view the images you are editing in Photoshop.
Light Work with subdued and consistent lights. Overly bright lights make the monitor appear dim and reflect light off the monitor. Dim lights can make the monitor appear overly bright and lead to eye fatigue as they move from the monitor to adjacent objects. Variations in room light will also change the appearance of images on your monitor. Standard 60–100-W tungsten bulbs are good room lights. You will also need a good, bright light for viewing your prints near your monitor. ...