The lenses of your Oculus Quest 2 are sensitive to direct sunlight and can be damaged by too much exposure and too much exposure can be less than a minute.
This can even happen indoors. If you leave your headset anywhere near a window and the lenses are exposed to sunlight that way, it can also damage the lenses permanently.
Also, be careful transporting it outside without a case or lens covers.
Generally the damage appears as dots on the lens that don’t move or change. We can’t promise anything, but what we’ve read is that Oculus have been fairly liberal with fixing this though it is not covered under the warranty.