You should wear squash goggles / squash glasses every time you play or practice squash.
Squash is played in close quarters and you don’t want a flying ball or racket to make contact with your eyes and potentially damage your eyesight. Plus, most squash facilities, squash leagues, and squash tournaments require you to wear protective eyewear on the court.
And yeah, I know the pros don’t wear goggles, but personally, I think that’s idiotic. I wear goggles, because one of my favorite things to do is use my eyes to look at stuff. That, and I know two guys who have permanent eye damage from squash.
(Still not convinced? Read this article by James Zug.)
Best Squash Goggles
Please note that in order to get sufficient eye protection, you need goggles with polycarbonate lenses. In the US, eyewear must meet something called the ASTM-F803 standard. It’s OK to wear contact lenses as long as you wear polycarbonate lenses over them. Regular eyeglasses and open eyeguards (with no lenses) are not safe enough to play squash with. You can read this research study for more information. If you wear prescription lenses, you’ll need to purchase prescription squash glasses. Talk to your optician about ordering a pair of these.
Squash Goggles Links
Here are some links to different brands of squash goggles. All the goggles posted at these links should meet the recommended ASTM safety standards, unless I state otherwise. To be safe, double check the product descriptions from whatever store you purchase from.