Mach Band Effect

http://www.nku.edu/~issues/illusions/MachBands.htm

Color

Use of Value and Color
http://www.echalk.co.uk/amusements/OpticalIllusions/colourPerception/colourPerception.html

http://www.yorku.ca/eye/simcont1.htm

Simultaneous and Successive Contrast

The Eye and Simultaneous Contrast

Achroma Value

Value Simultaneous Constrast in Achroma
http://www.michaelbach.de/ot/lum_dynsimcontrast/

http://www.yorku.ca/eye/simcont2.htm

Lit Sphere