Vision for sustained near vision tasks

Vision for sustained near vision tasks is the functional area that usually is assessed most carefully during the clinical evaluation and at low vision clinics. At school near vision tasks are common and therefore many tests have been designed to assess the child's reading ability and ability to see pictures with and/or without optical or electro-optical devices. As stated repeatedly on the previous pages, both the sensory and the motor functions related to sustained near vision tasks need to be assessed.

WHO/PBL/03.91 recommends that visual acuity is measured at distance and near and that similar optotypes are used for both measurements so that differences in distance and near visual acuity are identified.

In the report the values of visual acuity measured with single, line and crowded tests, reading acuity, contrast sensitivity, colour vision, visual adaptation speed and the quality of visual field are documented. After that the use of optical and non-optical aids and special lamps is discussed. The need for further training or requirements for other devices are evaluated. Once these vision enhancement techniques have been evaluated, vision substitution/ compensation techniques need to be discussed.

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