The eye-patch is an outdated and slightly harsh fix for this, at least for adults. There are now fresnel prism stickers you can stick on one of your glasses. This is extremely useful. They are available up to 15 degrees.
(Edit: Sorry the link doesn't work on the same page. Open it in a new tab or search for my other comment below.)
RE: Let's talk about STRABISMUS [The medical term we popularly know as half past four]