Terminology question

[rydel]

Is there a term for the optical illusion that makes light values appear to get brighter as it meets with a dark value and vise-versa?

[Elwell]

It's a form of simultaneous contrast, whether there's a more specific term for this particular phenomenon I don't know.

[k4pka]

Yeah Ive heard it called the "double contrast" effect. Same as Elwell really.