Since part of their water evaporates they practically dehydrate your eye by absorbing water out of natural tear film since the eye. It is usually during periods of high concentration (such for example front of computer) any person blinks less after which it begins to complain of dry eyes. http://temtrack.com/public/tr.php?c=240&clk=2364206549&mid=92248&ema=robert%40plantdelights.com&url=aHR0cHM6Ly9Xd3cuVGhlcmFsaWZlLmNvbS9kcnktZXllcy1hbmQtYWdpbmcv