There are two reasons that cause dry eye, and they are unrelated. The first is due to facial nerve damage, that many people here are experiencing. This causes inability for tear formation, which becomes even worse from the fact that the eye doesn't close.
The second reason is because of the 5th-trigeminal nerve damage, which is what you have from the symptoms you are describing. This causes lack of sensation to the cornea (as well of course to the rest of the face). Therefore the eye cannot "feel" when there is a lack of moisture, and is not sending the appropriate signal for tear production. the eye ends up beeing completely dry, and then you really start feeling it. If lack of corneal sensation is the cause, there is still tear production, just less. Therefore, you don't need to tape the eye, put eye drops too often etc - just a regimen of care with eye drops a few times a day is sufficient.
I didn't figure what was causing my eyes to be dry, until both eyes were really red and irritated (because the "good" eye tries to compensate for the lack of tear production from the AN eye). Following the excellent suggestions from the Cyberknife forum, as well as my optometrist, I experimented with several types of eye drops. As Michelle mentioned, my favorite ones are the Refresh Celluvisc - I use them twice a day, morning and night. And in-between, once a day I use the Genteal eye drops. My optometrist suggested that I can use drops as frequently as every 2 hours, if they are needed to keep the eye moist.
The problem of dry eye caused by the trigeminal nerve is annoying, but can be dealt with easily when following the proper care. Problems due to facial nerve damage are more challenging, and there is tons of information about this in this forum.
Marianna
