Skiascope

This skiascope was manufactured by John Trotter of Glasgow. John Trotter set up business in Gordon Street in the 1880s with a branch opening in Edinburgh in the 1920s. Trotter was a pioneer in many branches of optical science and he also advised hospitals on the instillation of X-ray apparatus.
Ophthalmic surgeon Hugh Wright Thomson worked with Trotter to develop the skiascope which he used initially for eye examinations in school children although he subsequently also found it helpful for adults in hospital refraction work. A long stem was attached to its centre and the circular frame was fitted with twenty of the lenses most commonly used in retinoscopy (technique to objectively determine the refractive error of the eye – farsighted, nearsighted, astigmatism – and the need for glasses).

c. 1905

2003/77.56

Diameter: 25.6 cm