The test comprises selected paper colour samples. On each page, four colour samples surround a central spot and the subject must choose the one that most closely resembles the colour of the central spot. Each page provides possible protan, deutan or tritan confusions that may be mixed with a normal response since some observers may find more than one near match on a page. A consistent regime must be used, taking care to illuminate the test correctly.
The Amsler grid is a test chart used to determine quality of central vision and allows the analysis of disturbances of visual function, which accompany the beginning and evolution of maculopathies. The standard chart to be used in this practical consists of a square with white lines on a black ba...
Children may become frightened as the clinician approaches closely, during direct ophthalmoscopy and co-operation could be lost. Also, children often look at the ophthalmoscope light and track it as the clinician moves, allowing examination of the macula but not the optic disc. Furthermore, the f...
The technique allows stereoscopic, wide-angled, high-resolution views of the fundus and overlying vitreous. Its optical principles and illumination options allow for visualisation of the fundus regardless of high ametropia, hazy ocular media, or central media opacities.