part of part of in taxon derived from ancestral fusion of derived from ancestral fusion of Sauria camera-type eye upper eyelid lower eyelid brille ocular scale there are transitional stages between total lid loss and full brille formation (Bellairs & Boyd, 1947). A layer of transparent, immovable disc-shaped skin or scale covering the eyes of some animals for protection, especially in animals without eyelids. The brille has evolved from a fusion of the upper and lower eyelids. In snakes, there is no eyelid and the brille is clear and cannot be distinguished except when the animal is becoming ready for ecdysis. At that time, it becomes cloudy and is visible as a cover over the eye. When the snake moults, the brille is also shed as part of its skin. The Brilles protect their eyes from dust and dirt and gives them a 'glassy-eyed' blank appearance Snakes, flap-footed lizards, night lizards, and some skinks have brilles. All geckos except those in the subfamily Eublepharinae (eyelid geckos) possess brilles. Fish also have transparent eyelids called adipose eyelids. UBERON:0010515 Wikipedia:Brille eye cap skin of face