Brush tip size disappeared

[Gadbury]

I accidentally pressed something when painting and now the brush tip size is not displayed as I paint and its hard to tell what I'm doing. I've tried cursor options and can't seem to get it back. Anyone know how to get it back to default?

[Tonic]

Caps Lock?

[Gadbury]

Great thanks, I wasn't sure what the key was and what it would have been called!