This is my personal favorite for night dry eye protection. It was developed by Eye Eco specifically to protect CPAP mask users from air leaks, but after its launch it quickly became my go-to product for a great many people for night dry eye protection with or without CPAP.
Onyix/Quartz shields are not necessarily the products that provide maximal moisture, but they provide more than adequate moisture for a great many of us and they are small, user-friendly, easy to keep clean, low profile, and in general just very unobtrusive. So although I consider EyeSeals 4.0 superior in terms of protection offered (as well as some other advantages) I have stuck with Quartz for my personal use.
For CPAP users, Onyix & Quartz should remain the first choice for most people except those with larger hat or orbit sizes who will want to go straight to the EyeSeals.
I also find that many users like to rotate between products depending on time of year and the severity of their symptoms, so far example they might use Onyix/Quartz in the spring and summer months and then go back to Tranquileyes or EyeSeals 4.0 for the fall and winter when they are battling heated dry eye at night.
Suggested best uses
First time dry eye shield users. This is the easiest one.
Users who want something low profile and lightweight. This is a great way to block all drafts and trap a fair amount of moisture without wearing anything large, thick, heavy or foam lined.
People who have skin reactions to the foam on Tranquileyes but for whom EyeSeals is too big or the material too heavy.
CPAP/BiPAP users. I have high confidence of the compatibility of this product with almost all masks. I very rarely hear from anyone who cannot get it to work properly with their mask. (It is returnable/refundable if it doesn't work out for any reason - please see return policy.)
Limitations
Sizing: Onyix & Quartz are too small for some users, or may sit too close to their eyes if they have large orbits and/or very long eyelashes.
Indentations: People who are prone to edema or who have very delicate, impressible skin around the eyes.
Alternatives to consider
Please see our Product Guide: Night Dry Eye Protection Devices for suggested guidelines on product choices.