Source:http://linkedlifedata.com/resource/umls/id/C0182044
UMD: Ophthalmic measuring instruments designed for objectively determining the curvature of the anterior corneal surface and the refraction of the eye (e.g., diopter, cylinder axis) by projecting illuminated images onto the patient's cornea. The instruments usually consist of light sources, a pair of objects to be projected onto the cornea, a telescope with prisms and lenses for reflecting and observing images, a device for adjusting the positions of the reflected images, and the software appropriate to calculate the corneal curvature and the refractive power. Ophthalmometers are used mainly for preassessment for refractive corneal surgery and for contact lens fitting.