I created a room with sea lanterns all around the outside and used powdered snow blocks to diffuse the light.

The north and south facing walls appear to be lit correctly, as well as the floor, but the east and west walls as well as the floor are not being correctly lit.

The light levels on all the blocks are correct so this appears to just be a visual bug. I also tested with light from Shroomlights and got the same results.

Reproduce

• Build a hollow box of powder snow
• Put a light emitting block all around the powder snow (like glowstone)
• Go inside the box
  Notice the east and west sides are darker then the rest

Expected Result

The powder snow blocks would all be evenly lit not on side being darker than the other