Noticed this recently, not sure if I messed with a setting in graphics or something changed.

Going on map I had made before so the change in lighting is easily noticed.

Basically the light almost looks like it is in fog but the map itself is clear. Then when you get fairly close it lights up from being dark and looking unlit...
The old turnip lamps had a sort of glow around the turnip but the face only lit up as I got closer to it. Looking like they are in a thick fog and getting close lets you see them.

Was this an optimization thing done at some point? Kind of not sure how much I like it... I suppose if they are just for "indoor" style lighting then it should be close enough inside to not notice... makes it kind of pointless for trail markers like in swamps though...unless they don't act like that in swamps? I could see it in the swamps but I am in the Meadows.