Also termed vision test, the refraction test is an examination that tests an individual’s ability to see an object at a specific distance. The test is performed by an optometrist or ophthalmologist in the doctor’s office. The refraction test involves looking through a device to read letters or recognize symbols on a wall chart through lenses of differing strength which are moved into and out of the device. This test is performed as part of a normal examination of the eye to determine whether an individual has normal vision. It is also used to determine the prescription for eyeglasses or contact lenses.
Not yielding, or not yielding readily, to treatment.
- Refractory anemia
Anemia that is unresponsive to treatment.
- Refsum disease
A genetic disorder that affects the metabolism of the fatty acid phytanic acid. When phytanic acid accumulates, it causes a number of progressive problems, including inflammation of numerous nerves (polyneuritis), diminishing vision due to retinitis pigmentosa, and wobbliness (ataxia) caused by damage to the cerebellar portion of the brain. Refsum disease is caused by mutations […]
To reproduce or renew something that was lost. For example, after an injury, the liver has the capacity to regenerate.
A plan or a regulated course, such as a diet, exercise, or treatment, that is designed to give a good result. A low-salt diet is one type of dietary regimen.