Patient Care

Color Vision Testing

Color vision is an important component of human vision. Defects in this can be by birth or due to any acquired diseases. The testing is done using one of the two methods.

During a VEP test, three or more electrodes are attached to the patient's head with an adhesive. The patient is then asked to stare at a strobe light or checkerboard pattern on a television screen. Each eye is tested separately. The electrodes record hundreds, sometimes thousands, of electrical responses from the patient's visual nervous system, and these responses are recorded by a special computer for interpretation by a physician.

CT scanning is a computerized system where in x- rays are used to construct images of thin slices of tissues allowing detailed evaluation of the tissues under consideration. By manipulating the soft ware, the image quality and detail can be enhanced. Injecting some drugs called contrast agents can get additional information. CT scanning is very useful in the evaluation of diseases of the orbit (bony cage in which the eye is located) as well as some diseases of the eye itself. Injury related problems - especially presence of foreign bodies is easily picked up and located on CT scanning.

MRI scanning is a different technology and looks at the tissues in a different perspective. Sometimes both CT and MRI scanning may be needed to understand some diseases. MRI is especially useful in diseases of brain that may affect the eye. By using some specialized soft ware, one can even image the blood vessels of the brain without injecting any drug ( MR Angiography).