refractometer

noun 0.825

refracting telescope

noun 0.750

reflector

noun 0.744

refraction

noun 0.742

refractivity

noun 0.692

refractometry

noun 0.667

refractory

noun 0.652

refractive index

noun 0.651

retroreflector

noun 0.639

reflecting telescope

noun 0.630

refracture

noun 0.625

refractive power

noun 0.621

reflectometer

noun 0.602

reflection

noun 0.591

prism

noun 0.590

radar reflector

noun 0.582

riflescope

noun 0.576

telescope

noun 0.575

retractor

noun 0.571

retinoscope

noun 0.569

parabolic reflector

noun 0.568

resonator

noun 0.564

deflector

noun 0.561

collimator

noun 0.558

refection

noun 0.554

spectroscope

noun 0.553

reflection nebula

noun 0.551

rectifier

noun 0.550

fresnel

noun 0.550

receptor

noun 0.548

lens

noun 0.547

interferometer

noun 0.547

reflecting

noun 0.546

repeater

noun 0.545

reframe

noun 0.544

reflux condenser

noun 0.544

photoreceptor

noun 0.543

refrigerant

noun 0.540

reflectivity

noun 0.540

dioptric

noun 0.539

diffraction

noun 0.537

gravitational lens

noun 0.536

diffuser

noun 0.536

reft

noun 0.535

beam splitter

noun 0.535

reflux

noun 0.531

absorber

noun 0.531

reflectometry

noun 0.529

retractive

noun 0.529

convex lens

noun 0.529

birefringence

noun 0.527

revelator

noun 0.527

referee

noun 0.525

transceiver

noun 0.525

radiometer

noun 0.524

reagent

noun 0.524

spectrometer

noun 0.522

magnifier

noun 0.521

reefer

noun 0.521

rebreather

noun 0.521

reframing

noun 0.520

refrigerator

noun 0.520

rector

noun 0.520

diopter

noun 0.519

diffraction grating

noun 0.519

magnifying glass

noun 0.517

polarimeter

noun 0.516

monochromator

noun 0.515

scintillator

noun 0.514

receiver

noun 0.514

spectrograph

noun 0.513

condenser

noun 0.513

reflex

noun 0.512

rejecter

noun 0.511

rangefinder

noun 0.511

reproducer

noun 0.510

reformer

noun 0.510

reflexion

noun 0.510

photoreflectance

noun 0.509

microscope

noun 0.509

optical glass

noun 0.508

optical flat

noun 0.507

concentrator

noun 0.507

reamer

noun 0.506

repeller

noun 0.505

ray

noun 0.503

autocollimator

noun 0.502

retransmitter

noun 0.502

calibrator

noun 0.502

infuser

noun 0.502

crystallographer

noun 0.501

protractor

noun 0.501

fluorescent

noun 0.501

reticle

noun 0.501

spyglass

noun 0.501

radio telescope

noun 0.500

recurve

noun 0.500