How come the crested gecko has no eyelids?

In my theory it may be something to do with being nocturnal; however as an alternative they lick their eyes

The crested gecko (R.Cilatus) is a nocturnal species and have no eyelids, as the leopard gecko (e.Macularis) is a nocturnal species and do have eyelids. In every environment is a food chain, Geckos are not so high on the charts and almost anything can eat an animal that weighs 30-80Grams and only reach 9". Being an arboreal species living 3-12Feet of the ground, any predator over top can quickly snatch a crestie with ease. Crested geckos (along with all of their closely related cousin's [R.leachianus, R.Sarasinourim, R.auriculatus, R.chahoua etc.]) are animals with extremely weak jaws (in comparisson to other gecko species), robust body's, and an anchor as a tail, must be aware of their surrounding's. Their eyes being fixed open at all times allows them to do so. Most species of gecko with eyelids, are ground dwellers and usually burrow within the dirt. Having the ability to close their eyes keeps dirt, sand and mud from entering the eyes.