To view these images as the artists intended
calibrate your monitor.
You don’t really need special calibration equipment, especially since these images are coming to you via your browser ie: FireFox, Internet Explorer, Google Chrome, and others. FireFox has color management but the rest…Well lets just say its hit or miss.
For a quick fix use this test patch. Make sure you can barely distinguish between the whitest white and its nearest neighbor. Use the contrast to adjust.Then make sure the blackest black and its slightly lighter neighbor are adjusted using the brightness control.
That is probably the best that can be expected considering the many variables influencing the delivery of images on the internet.
Try using Calibrize on your computer to make sure your monitor is setup properly.