trial lenses

tri·al lens·es

a series of cylindric and spheric lenses used in testing vision.

tri·al lenses

(trī'ăl lenz'ĕz)
A series of cylindric and spheric lenses used in testing vision.
References in periodicals archive ?
To achieve 10% magnification using a pair of trial lenses separated by 12mm you would place:
A case from 1894 containing 43 pairs of metal-rimmed and goldrimmed trial lenses, plus two trial frames.
When you're being fitted for contacts, make sure your eye health professional provides you with a pair of trial lenses before ordering the final pair.
After the lieutenant put the trial lenses in his eyes, I checked his vision and the fit.
He said: "There is not much data about the issue but the re-use of trial lenses did not seem to us a good idea.
Refractive errors are currently measured using trial lenses, which do not measure higher order aberrations and rely on subjective patient feedback.
Of course, during an assessment, the pre-reg will probably only have a selection of trial lenses to choose from so, unless they are lucky, they are not likely to get 6/6vision, or an alignment fit.
If your eye doctor decides you are an appropriate candidate for either ACUVUE or SUREVUE contact lenses, he or she will fit you with a free pair of trial lenses.
Once a colour is selected, it is reproduced in tinted trial lenses which can then be tested by the patient in the context in which they are going to be used, for example in the appropriate lighting conditions.
The time taken to fit toric contact lenses can be minimised by ensuring that your practice carries a good stock of trial lenses.
It is preferable to use single trial lenses or a lens rack.
Of course, during your assessment you will probably only have a small selection of trial lenses to choose from so, unless you're lucky, you aren't likely to get 6/6 vision or an alignment fit.