埃德姆•马略特发现盲点不是因为他仔细观察过视觉现象,而是因为他解剖过很多眼睛。 How did Edme Mariotte Discovered the Blind-Spot?
As we all know, in each of the two eyes in every one of us, there is a blind spot. In some ophthalmology textbooks, the blind spot is also called the Mariotte spot, as it was first discovered by French scholar Edme Mariotte in 1660s.(see: http://en.wikipedia.org/wiki/Edme_Mariotte)
How did Mariotte discovered the blind spot? He discovered it not by carefully observing the visual world in front of him, but by dissecting eyes from both humans and other animals. As he found that the optic disk in the retina lacks any photo-receptors, he reasoned that there must be a blind spot in the eye's visual field corresponding to this optic disk in the retina; and from there he figured out a procedure to delineate (or detect) the blind spot.
From this story, it is reasonable to state that it is very difficult, if not completely impossible, to discover the blind spot without some detailed knowledge about the anatomy of the human eye.