Bad mask design is a cause of dry eye
I'm writing as a CPAP user of 15 years to point out something that many of you may have not realized, and maybe get the ball rolling to see if manufacturers start addressing this: your dry eyes may be the product of bad mask design.
For many years I suffered from dry eye on and off, some years it got really bad, then I realized what was happening: the exhaust ports of the mask I was using were at eye level, and no matter how forward facing the stream of air was it ended up bouncing against the bed or pillow and desiccating my eyes for hours straight.
To test my hypothesis I plugged the exhaust ports with some epoxy resin and opened new ports on the bottom of the mask, the problem was solved, no more dry eye, no need for expensive eye drops anymore.
But now I have a new problem: my current provider only carries masks that have a ring shaped exhaust around the part where the tubing is attached to the mask, and so the dry eye is back, there's no way to fix this type of mask.
It seems like manufacturers and providers are not aware of this issue, perhaps if we start pointing it out they will improve their designs or provide some alternatives. In the mean time if you are a CPAP user with dry eyes and your mask has exhausts at eye level changing it might make a huge difference.