What are those funny frames called that the doctor uses with test lenses? What are the names of common instruments used to measure your vision? - Rob

Cara

Glasseslover

The large unit, usually black in color, that is suspended over the chair is called the phoropter. It consists of many plus and minus sphere combinations internally, as well as cylinder lenses internally that can be rotated for axis. It also has pinholes, plus & minus .25 spheres, and an occluder. On the front outside are "cross cylinders" for fine tuning astigmatism corrections and prisms.

In addition to a phoropter, the doctor may use a retinascope which can give a rough idea of sphere corrections as well as a brief look at the retina, an opthalmoscope which gives a more detailed look at the interior of the eye including the retina and the macula.

In recent years, auto refractors which come very close to prescribing without any response from the patient have become very common as well as "puff" tonometers to measure intraocular pressures. There are many others available to the doctor, but these are the ones used mainly.