20w46a, 20w48a, 20w51a, 21w03a, 21w05b, 21w06a, 21w07a, 21w08b, 21w15a, 21w16a, 21w17a, 1.17, 1.17.1, 21w42a, 1.18, 1.18.1
When a player is inside powder snow blocks, their view is limited to about two blocks. When a player is inside powder snow blocks and they have the blindness status effect, their view is limited to the same range as the blindness effect.
1. Create a new superflat world in creative mode (survival also works as long as commands are enabled).
2. Place between two and four solid blocks like dirt between 0,0 and 15,15
3. /fill 0 4 0 15 5 15 minecraft:powder_snow replace air
4. Step into the powder snow -> field of view is limited to about 2 blocks
5. /effect give @p blindness -> field of view expands to the range of the blindness effect, when no change or a smaller field of view would be expected. The dirt blocks can be seen
The fog from powder snow isn't rendered when players have the blindness effect.
The fog from powder snow would be rendered when players have the blindness effect.