McHardy type perimeter, London, England, 1885-1930

Perimeter, McHardy's type by Curry and Paxton, London, 1885-1930 Perimeter, McHardy's type with spare candles and chart

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Perimeter, McHardy's type by Curry and Paxton, London, 1885-1930
Science Museum Group
© The Board of Trustees of the Science Museum

Perimeter, McHardy's type with spare candles and chart
Science Museum Group Collection
© The Board of Trustees of the Science Museum

Perimeter, McHardy's type by Curry and Paxton, London, 1885-1930

Perimeters were introduced in the 1850s to locate the visual field defects. These are sometimes referred to as ‘blind spots’. This type was designed in 1882 by leading ophthalmic surgeon Malcolm MacDonald McHardy (1852-1913). It was made by Curry and Paxton of London.

The patient punched a circular chart when the target, a square of coloured paper, moved out of view. The mechanism mapped their field of view.

Details

Category:
Ophthalmology
Collection:
Sir Henry Wellcome's Museum Collection
Object Number:
A606421 Pt1
Materials:
metal, plastic and string
Measurements:
overall: 545 mm x 462 mm x 175 mm,
type:
perimeter