Highest hyperacuity
Who
Dr Dennis M. Levi
Where
United States (College of Optometry, University of Houston.)
When
The human eye is capable of judging relative position with remarkable accuracy, reaching limits of between 3 and 5 seconds of arc.
In April 1984, Dr Dennis M. Levi (USA) of the College of Optometry, University of Houston, Texas, USA, repeatedly identified the relative position of a thin bright green line within 0.85 seconds of arc. This is equivalent to a displacement of some 6 mm (0.25 in) at a distance of 1.6 km (1 mile).