I'm using a macbook air 13" (2014). The terminal commands below make fonts slightly more tolerable to my eyes. Enter without the quotes.
"defaults write -g AppleFontSmoothing -bool True"
"defaults write -g AppleFontSmoothing -int 2"
Confirm setting with:
"defaults read -g AppleFontSmoothing"
To return to Apple's original setting:
"defaults delete -g AppleFontSmoothing"
Make sure LCD smoothing is enable under General in System Preferences. You might need to log out or restart before the changes take effect.