The College of Optometrists

The Lister perimeter, supplied by Theodore Hamblin Ltd, consisted of a rotating arc with sliding colour targets. There was a lamp holder with a directional shade. Note also the adjustable double chin rest, a round chart holder and an integrally mounted case of white, green and red colour targets.

From quite an early period various instruments existed to detect a patient's blind spot and to detect pathological change in his visual field. Even today a simple target fixation test may be employed, using nothing more sophisticated than a pen, for example.

The first attempt to achieve a diagnostic result dates from 1856 when the Berlin ophthalmologist Von Graefe (1828-1870) used a campimeter to examine the visual field of a patient with amblyopia.

1857 Herman Aubert constructed the first dedicated investigational perimeter (an arc-shaped instrument later perfected by Richard Förster to whose name this type became attached).

1860s Perimeters were built with automatic recording devices.

1872 Scherk introduced the hemispherical perimeter. This type remained a much less popular version until after the Second World War when larger electronic visual field plotters were designed along superficially similar lines.

This perimeter has been attractively cased in a compact manner. It has a brass base and stem, a black metal head, rest and arc. The precise date and maker are unknown but this is a high quality instrument.

1888 A hand-held version by Schweigger was pioneered for use at the patient's bedside. This was quite small, the arc was just 20cm in size, in contrast to the heavy clinical instruments that often filled huge crates.

To the left are two hand-held perimeters with two arcs, including chin rests. Such instruments continued to be used into the later twentieth century and assigning a date to these speciifc examples is very difficult.

Below is a dismantled perimeter in a crate by John Weiss & Son Ltd. It probably dates from around 1900. As practitioners often assembled their instruments and discarded the packaging this is a rare survival.

1920s Illuminated arcs were introduced. Some models now projected the test object thereby avoiding giving the patient a giveaway hint of where to look due to mechanical noise.

1945 Goldmann published on the principles of quantitative perimetry and his instrument set the standard for most post-war models.

Modern perimeters are often computerised. Some provide something akin to a sealed environment for the patient's head. Instructions on how to look for the lights and how to record spotting them are given by a recorded voice which may also offer encouragement along the lines of 'You're doing really well'.