I have Optifine installed, not sure if that's doing something with it, but the sky has these odd white shapes pointing at my "cross hair":

https://imgur.com/a/iv7dg

ok looks interesting, does this also happen without optifine ?

Yea gave it a shot and still did it.. really weird. Does do it during the day, but not as much.

This is most likely caused by optifine.

@DigitalSketch

Has it worked with any older OptiFie version?
You can try to disable Fast Render, Shaders, AA and AF.