Amoils ACU-12 ophthalmic cryosurgical unit, aluminium case, by Keeler Instruments Ltd., England, 1980

Cryosurgery involves the use of extreme cold to destroy tumours and other abnormal and unwanted tissues and has been practised since the late 1800s. This equipment is used in cryosurgery on the eye. In particular, to treat trichiasis (caused when eyelashes grow in towards the eye) and repair rips to the retina to prevent any further damage, such as retinal detachment.

In the case of retina repairs, the pencil-like cryoprobe at the end of the wire would be placed on the rip of the retina and cooled using carbon dioxide. This leads to the formation of a scar which holds the retina to the underlying layer. Cryosurgery can be performed under both local and general anaesthetic. The equipment was made by Keeler Instruments Ltd.