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
Retinoscope
An ophthalmic instrument designed to assess objectively refractive errors of the eye by reflecting a beam of light into it from a mirror and observing the movement of the retinal reflex across the pupil. NOTE - A retinoscope usually consists of an illuminating system to produce a beam of light including a mirror with either a semi - reflective or perforated highly-reflective coating, a viewing system and a power supply for the light source.