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Testing vision in children can be a challenge, the younger the child the more challenging the task. Often more than one test has to be performed on more than one occasion to get a reasonable grasp on the child's vision. There are several different tests in vogue, some more suited for certain age groups than others.1 In 1896 Claud Worth introduced the ‘ivory-ball test’, which could be used for testing vision in children who are old enough to walk, usually between the ages of 1 and 3 years. It consists of a set of five ivory balls varying in size from 0.5 ins to 2.5 ins (cover image). …
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