Optometrists are trained to examine eyes and prescribe visual aids such as spectacles. The optometer pictured in the media section of this document dates from the 1800s. The optometer was used with various lenses to determine the refraction of the eye. Refraction means the extent to which light is bent by an individual's eye. The result can determine how short-sighted or long-sighted they are, and the strength of spectacles required. In the second half of the 1800s, ophthalmologists also devised instruments to measure the separate components of vision. Dr Jules Badal developed the pictured instrument in 1876. It was based on an optometer invented by William Porterfield in 1759. The brass stands look as though they were made for an optometer to be table mounted, with heavy brass stands and designed to hold a cylindrical object securely as would be required by an optometer. Stands appear to have been very well made and very early probably early to mid 19th Century by a well known scientific instrument maker given there are no inscriptions or marks to indicate the time period made or maker it is difficult to assume significance to these items at this point in time as well as the items are incomplete.The brass stands believed to be for mounting an early Optometer an (ophthalmic instrument) Noneflagstaff hill, warrnambool, shipwrecked-coast, flagstaff-hill, flagstaff-hill-maritime-museum, maritime-museum, shipwreck-coast, flagstaff-hill-maritime-village, stands for scientific instrument

How widely the prisoptometer was used is unclear but the Standard Optical Company later patented a new model, The Standard Prisoptometer, on June 21, 1904. Edward Jackson's crossed cylinder technique of determining astigmatism was first detailed in the Transactions of the American Ophthalmological Society (1887)4:595-598. The convenience of Jackson's crossed cylinder lenses over the prisoptometer in weight, cost, portability and reliability meant that they were soon almost universally adopted.This is a rare item as few are known world wide.This instrument is an optometer, that is, a device to measure the refractive error of an eye. It is made of cast iron, steel, brass and glass. It contains a prism which could be rotated, and was used to view a disc or an object circle. The prism caused monocular doubling of the object circle and the separation of the two images varied as the prism rotated, depending on the astigmatism present. The axis of the astigmatism was indicated by the prisoptometer and trial lenses were used to determine the the magnitude of the spherical and cylindrical refractive errorImprinted:"DR CULBERTSON'S PRISOPTOMETER/ GENEVA OPTICAL COMPANY MAKERS, GENEVA, N.Y./ PATENTED SEPT, 21, 1886". Stamped "853" on eyepiece and lens mounting.optometry, prisoptometer, optometer, astigmatism, refractive error, refraction, culbertson

This is one of a collection of items associated with Dr Felix Henry Meyer (1858-1937). Meyer was a very prominent early obstetrician and doctor, playing a part in the establishment of the role of the chair of obstetrics at the University of Melbourne in 1929. He was also a foundation member of the Royal Australian College of Surgeons.Metal optometer. Consists of a glass lens, metal scale and a sliding sight test plate. The words 'CONVEX' and 'CONCAVE' are engraved on the side of the scale. Top of the scale is engraved with various measurements. Test plate is engraved with the words 'COUNT THE DOTS' and a series of dots.optometry