Uberon definition : Orifice separating upper and lower eyelids. In the human adult this measures about
10mm vertically and 30 mm horizontally. It can be reduced in size in fetal alcohol
syndrome. In Trisomy 9 the palpebral fissures can be upslanting. [WP,modified].;
Orifice separating upper and lower eyelids. In the human adult this measures about
10mm vertically and 30 mm horizontally. It can be reduced in size in fetal alcohol
syndrome. In Trisomy 9 the palpebral fissures can be upslanting. [WP,modified].