optical appliance

(redirected from optical aid)

appliance, optical 

Any optical system which is used in conjunction with the eye. Optical appliances include spectacles, contact lenses to correct sight and/or anomalies of binocular vision and also telescopes or microscopes to magnify an object. Syn. optical aid. See optical dispensing; ptosis.
References in periodicals archive ?
Do not use optical aid like telescopes or binoculars - you will be blinded before you can even blink.
Widely used standards are inadequate when it comes to specifying visual inspection in terms of magnification, as the manner in which an optical aid is used impacts its magnification.
Twist-up eyecups, an oversized center-focus wheel with integrated adjustable diopter for instant focus capabilities, a padded aircell neck strap and a padded case with shoulder strap complete this precision elk-locating optical aid.
There is another technique we can use to see fainter things, with or without optical aid, known as "averted vision".
Be careful though, don't look at the sun directly with or without optical aid as permanent eye damage may result, wait until the sun has completely disappeared.
In other words, in terms of brightness the star and the planet would have appeared as a single, very faint star almost at the threshold of visibility without optical aid.
However, optical aid will greatly improve the view, allowing viewers to see exquisite detail," he said.
The author does not assume that the reader will own a telescope, and there is plenty here that will be of value to the binocular user and to those with no optical aid at all: indeed, the wide-angle sky charts that accompany the seasonal constellation notes are well suited to the naked-eye observer.
With the beginning of April, the comet was estimated at magnitude this is still about 250 times dimmer than the faintest star that one might see without any optical aid.
Only with optical aid can a connoisseur's gaze penetrate into the inmost depths of the 7.