Magnification is the experience of distant details within one's visual field appearing magnified and closer than they actually are.  This can give the perception that one is seeing objects from greater distances than is usually possible within everyday life.
At its lower levels, this can allow people to see nearby objects (such as within reaching distance) as much closer than they really are, resulting in the perception that their visual capabilities have been somewhat enhanced.  At its higher levels, this can induce the perception of seeing distant objects as if they were right in front of the user despite their distance. These distances can range from several feet to hundreds of meters. Alternatively, it can also result in states in which a person's vision will zoom into the minute details of a small object, allowing them to see it from a perspective similar to that of a microscope. Since this is almost certainly a physiological impossibility, it suggests that higher level magnification may actually be a seamless hallucinatory state in which the details of distant visual input are predictively simulated in a realistic and convincing manner.
This effect is considerably more likely to occur if a person spends extended periods of time staring at an object or scene within the distance.
Magnification is often accompanied by other coinciding effects such as visual acuity enhancement and increased pareidolia. It is a rare effect that is most commonly induced under the influence of moderate dosages of psychedelic compounds, such as LSD, psilocybin, and mescaline.