Answer: Size

Alice in Wonderland Syndrome is a disorienting neurological condition wherein the afflicted patient may experience any number of vision related issues like micropsia (objects appear smaller than they actually are), macropsia (objects appear larger than they actually are), pelopsia (objects appear nearer than they actually are), teleopsia (objects appear much further away than they actually are), or size distortion of other sensory modalities. It is important to note that these symptoms are not caused by a bio/mechanical abnormality in the eyes of the patient, but by neurological action within the brain.

Although people may sometimes experience Alice in Wonderland Syndrome as a result of a benign (or at least transient) condition such as extreme exhaustion (lack of sleep) or migraine headaches, the condition can also signal a much more serious condition like brain tumors or viral exposure (some research indicates that the altered perception can be the initial symptom of the Epstein–Barr virus, a.k.a. mononucleosis, for example).

As the name of the condition more than implies, it’s named after the experiences of the titular character in Lewis Carroll’s novel Alice’s Adventures in Wonderland wherein Alice experiences many situations where various food stuffs and potions shrink and enlarge her. There has even been some speculation, though difficult to substantiate more than a century and a half after the fact, that Carroll was influenced to write about such experiences based on his own visual hallucinations brought on by migraines and epilepsy.