In lower vertebrates, the pineal gland has an eye like structure and it functions as a light receptor and is considered by some to be the evolutionary forerunner of the modern eye.

• 在较低等脊椎动物里，松果体有一个类似眼睛的结构而它的功能如同光的受体,一些人认为是现代眼睛进化早期的样子。