A perspective distortion is a subtle to extreme change in how a person perceives the size and distance attributed their body, to specific parts of the external environment, or to the external environment as a whole.  This effect is capable of manifesting itself in 4 different ways which may reflect the failure of each respective responsible visual function.     
- Macropsia - Objects are perceived larger than their actual size.
- Micropsia - Objects are perceived smaller than their actual size.
- Pelopsia - Objects are perceived nearer than they actually are.
- Teleopsia - Objects are perceived much further away than they actually are.
Alice in Wonderland SyndromeFeelings of suddenly having an impossibly giant or tiny body are also a very common manifestation of this effect. This feeling is already known by the scientific literature as “Alice in Wonderland Syndrome”, where it is seen as a temporary condition often associated with migraines, brain tumours, and the use of psychoactive drugs.   The effect can either be attributed to the body as a whole or specific parts of it. For example, feelings of having a huge head or tiny limbs are possible.
- Schneck JM. Macropsia. Am J Psychiatry 1965; 121:1123-1124. | https://doi.org/10.1176/ajp.121.11.1123
- Macropsia (medical dictionary) | https://medical-dictionary.thefreedictionary.com/macropsia
- Micropsia (medical dictionary) | https://medical-dictionary.thefreedictionary.com/micropsia
- Pelopsia (medical dictionary) | http://medical-dictionary.thefreedictionary.com/pelopsia
- Telopsia (medical dictionary) | https://medical-dictionary.thefreedictionary.com/teleopsia
- Abraham, H. D. (1983). Visual phenomenology of the LSD flashback. Arch Gen Psychiatry, 40(8), 884-889. | https://doi.org/10.1001/archpsyc.1983.01790070074009
- Horowitz MJ: Flashbacks: Recurrent intrusive images after the use of LSD. Am J Psychiatry 1969;126:565-569. | https://doi.org/10.1176/ajp.126.4.565
- Hamilton M (ed): Fish's Clinical Psychopathology. Baltimore, Williams & Wilkins Co, 1974. | https://books.google.com/books?hl=en&lr=&id=gHdQTZNkA9YC&oi=fnd&pg=PA1&dq=Hamilton+M+(ed):+Fish%27s+Clinical+Psychopathology.&ots=okWOwjZJfq&sig=Y85lNwTChlGIhtdhohkn-MXSyCA#v=onepage&q=Hamilton%20M%20(ed)%3A%20Fish's%20Clinical%20Psychopathology.&f=false
- Blom, J. D. (2016). Alice in Wonderland syndrome A systematic review. Neurology: Clinical Practice, 6(3), 259-270. | https://doi.org/10.1212/CPJ.0000000000000251