Visual Function Examination
Vision is mainly limited to the optics of the eye through the anatomy and physiology of the visual system. In this way, vision acuity may be a key clinical measure to show the integrity of visual pathway optical and physiological states of the eyes. Each patient must first have a routine examination of the vision acuity, regardless of the initial visit or follow-up visit. The central vision is the main sign of visual function, especially the far sight, which needs more attention. Whenever possible to use standard visual acuity chart (Snellen, ETDRS): A set of letter is set up, each letter as an integrity which is five times as large as each stroke; for patients who cannot read should use the none text chart (such as E, Landolt C) which is based on the same principles of the Snellen chart; for kindergarten children, use Allen cards, HOTV letters, or E games; for babies, use color objects, toys, or flashlights to determine vision by fixing or following objects.