- An arc of white light shone through the carefully planned refractors near its crest, making the Citadel look like an archer's bow drawn to the sky.
- He contributed to the theory of refraction, and as a result of his theory of the wave form of light he was able to calculate the refraction within the lenses and make refractors with lesser chromatic and spherical aberration.
- Each GSP student builds a complete 60-mm diameter f / 12 refractor and mount.
- Your doctor may use a computerized refractor to measure your eyes and estimate the prescription you need to correct a refractive error.
- The results demonstrated that trained nurses and lay screeners achieved similar accuracy rates administering the two automated refractors.