We recently heard from a long-time listener who couldn't recall if there is a name for the phenomenon he described this way: "You know those three-way mirrors in alcoves of department store dressing rooms? When you peer out of the corner of your eye, your body seems to disappear into a ribbon of ever-smaller reflection of yourself. It reminds me of the way railroad tracks dissolve into the distance…Is there a word for this visual effect?" (来源：英语杂志 http://www.EnglishCN.com)

We would guess psychologists might have a term for this disappearing self, but our correspondent asked for the name for the visual effect. Since the late 1700s, the place at which a group of receding parallel lines seem to meet when represented in linear perspective has been known as the vanishing point.

The especially perspicacious among us may feel compelled to point out the ever-smaller reflections in the three-way-mirror are not parallel to each other; still, the point of identifying perspective, that is, the technique of representing on a plane or curved surface the space relationships of natural objects as they appear to the eye, remains.

The original sense of perspective, by the way, referred simply to "an optical glass, as a telescope," and piece of perspective to "a picture painted so as to appear distorted or confused except when viewed from a single viewpoint." Those senses are now archaic and obsolete respectively, but perspective survives.