Some of the text appears blurry

I’m not sure if I clicked something that turned on a setting or what, but lately the text becomes blurry suddenly while I am typing.

When I first add text it appears normal. Then seemingly randomly this happens:

link to screenshot on - click the eye icon to view

Please help!

MacBook Pro (Retina, Mid 2012)
2.3 GHz Intel Core i7
8 GB 1600 MHz DDR3
NVIDIA GeForce GT 650M 1024 MB