R
- Radiance L
- reading cap
- reading portion
- reduce-aperture trial case lens
- reduced aperture trial frame
- reduced-aperture lens
- Reference distance
- reference IOP
- Reference plane
- reference seeing distance (RSD)
- reference wavelength
- refracting angle
- refracting edge
- refractive index
- Refractor head
- relative distance magnification
- relative visual attenuation coefficient
- resolution
- resolving power of the fundus camera
- retinal hazard limit
- Retinoscope
- reverse polarity system
- round segment
relative visual attenuation coefficient
Ratio of the luminous transmittance of a tinted lens for the spectral radiant power distribution of the light emitted by a traffic signal TSIGN to the luminous transmittance of the same lens for CIE illuminant D65(TV) where TSIGN is the luminoustransmittance of the lens for th spectral radiant power distribution of the traffic signal light.
NOTE: Q-values may be determined for each of blue, green, amber (yellow) and red signal lights.
