| OPT | opacity to light |
|---|---|
| OPT | a physical phenomenon related to or involving light |
| OPT | optical device having a triangular shape and made of glass or quartz |
| OPT | a pyrometer that uses the color of the light emitted by a hot object |
| OPT | an astronomical telescope designed to collect and record light from cosmic sources |
| OPT | in an optical manner |
| OPT | a worker who makes glasses for remedying defects of vision |
| OPT | the branch of physics that studies the physical properties of light |
| OPT | most desirable possible under a restriction expressed or implied |
| OPT | in an optimal and most desirable way |
| OPT | the act of rendering optimal |
| OPT | act as an optimist and take a sunny view of the world |