A patient may complain that an object appears larger or smaller than it actually is due to a number of conditions.
Causes of things looking larger than they really area (macropsia):
(1) exposure to a miotic agent
(2) spasm of accommodation
(3) use of excessive plus lenses
Causes of things looking smaller than they really area (micropsia):
(1) suboptimal accommodation
(2) atropine or scopolamine
(3) bolulism poisoning
(4) diphtheria
(5) presbyopsia
(6) use of excessive minus lenses