Howell Phoria Card
 Catalogue Number: 4231 Howell Phoria Card Category: Equipment Sub-Category: Tests of binocular vision Designer/inventor: Howell. Edwin Time Period: 1940 to 1999 Place Of Publication/Manufacture: Melbourne Publisher/Manufacturer: Cyclopean Design Description Of Item: Thick white plastic ovate near phoria card, 302 mm x 250 mm, designed to be used at 33 cm with 6 BD dissociating prism before the right eye. At centre of card is a scale with thick black lines above and below it which act as an accommodation lock. One side of scale printed in light blue with even numbers measuring exophorias. 'NEAR PHORIA CARD 33 cm' printed in light blue at top of card and 'CYCLOPEAN DESIGN' printed along base. Reverse s of card has a paragraph in N 7 print, cross cyl target, near letter chart and 6 simple three letter words so the card can also be used for other near point tests. Gradient AC/A ratio can be determined using lens flippers. At base is 'HOWELL TEST CAR'D with a copyright symbol, 'CYCLOPEAN DESIGN, 204 CANTERBURY ROAD, HEATHMONT, VIC 3135, AUSTRALIA, (03) 9729 5822'. Instruction sheet included with card. Historical Significance: This card was originally designed by Peter Dwyer, then President of the Vic Division of AOA, as an improved way of measuring near phorias in vision screenings provided by volunteer optometrists at the annual Melbourne Lord Mayor's Camp for disadvantaged children, He modified the Prentice card by printing hand-held A4 cards, coloured coded for eso and exo deviations. Ed Howell postulated that measurements would not be valid because of the peripheral fusion cues provided by the vertical sides of the card. Considering this possibility, Peter Dwyer rounded the sides into the ovate shape, referring to the modified shape as 'Howell Corners'. How Acquired: Donated by Colin Bates Date Acquired: 17/07/2017 Condition: Excellent. Location: Archive office. Pamphlet and ephemera filing cabinet. Drawer 10 |