This may give your eyes an extra little set.
The reason is that an RGP lens is constructed out of polymeric materials and don't contain water. You may also check on books having acne damage to some ideas. http://davincisurgeons.com/__media__/js/netsoltrademark.php?d=www.Opticaljournal.com%2Fsleep-apnea-and-dry-eye-syndrome%2F