I woke up this morning (using the latest version of Photoshop on a Mac) and my brush and eraser don't work at the edges of the brush. I have no idea what I could have done.
Here's a screen shot of both, brush and eraser.


What could cause this? It wasn't doing it last night. What setting(s) do I need to change. I've been using Photoshop for 25 years and never seen anything like this.