The bug
When you are under lava and give yourself Blindness, the blocks immediately around you become fully visible and the lava tint disappears. This also occurs with water, but is less noticeable.
How to reproduce
Linked issues
is duplicated by 2
relates to 2
Comments 4
Cannot reproduce in 20w17a either, the lava tint turns black but you can still only see 1 block in front of you (instead of several blocks away like in the video). Water is now affected by MC-4647 instead. If anyone is still able to reproduce the original issue, please comment and attach a screenshot if possible.
Was able to reproduce this on Minecraft 1.12.2.