Everything is Getting Highlighted

Put the summary of the bug you're having here

What I expected to happen was...:
So I was just mining and i didn't have any torches so i turned my brightness all the way up and i thought it would be fine

What actually happened was...:
All the blocks were getting highlighted with a weird texture, it was just black, gray, and white. it even does this whenever i am in the nether fortress.

Steps to Reproduce:
1. Just walk into a dark place with no torches or anything that could light it up (ex. a cave)
2. Just look around
3. ...