There is only one known species of primate that still has a functioning third eyelid, and that is the Calabar angwantibo (closely related to lorises) which lives in West Africa.

• 只有一种一直的灵长类动物还保存着第三眼睑的功能，就是生活在西非的金熊猴（跟狐猴是近亲）。