The function of the retroreflection component is to direct the reflection back to or near to the source of the light.

The effect is known as retroreflection.

There are several ways to obtain retroreflection:

Glass-bead screens exhibit a phenomenon of retroreflection; the light is reflected more intensely back to its source than in any other direction.

It uses the principle of retroreflection to alert another road user of the bicycle's presence on the road.

These beads provide initial retroreflection.

Performance requirements are included for color, retroreflection, and minimum areas, as well as the recommended configurations of the materials and design.

Some surfaces exhibit retroreflection.

In that case, the sphere surface behaves as a concave spherical mirror with the required curvature for retroreflection.

Testing for retinal retroreflection (red-eye effect)

In this application perfect retroreflection is not desired, since the light would then be directed back into the headlights of an oncoming car rather than to the driver's eyes.

Because there is no special control of upward light, high beams also cause backdazzle from fog, rain and snow due to the retroreflection of the water droplets.

The incident light from the transmitter system is both modulated by the MRR and reflected directly back toward the transmitter (via the retroreflection property).

If the illumination source is offset from the optical path, then the pupil appears dark because the retroreflection from the retina is directed away from the camera.

Unfortunately, at the perpendicular direction used for gain measurement, mirror reflection and retroreflection are indistinguishable, and this has sown confusion about the behavior of high gain screens.

However, phase-conjugate mirrors have an inherently much greater accuracy in the direction of the retroreflection, which in passive elements is limited by the mechanical accuracy of the construction.

These approaches have many advantages and disadvantages relative to one another with respect to such features as power use, speed, modulation range, compactness, retroreflection divergence, cost, and many others.

The orb artifact can result from retroreflection of light off solid particles (e.g., dust, pollen), liquid particles (water droplets, especially rain) or other foreign material within the camera lens.

The reversed beam is called a conjugate beam, and thus the technique is known as optical phase conjugation (also called time reversal, wavefront reversal and retroreflection).

Digital compositing programs and chroma environments use retroreflection to replace traditional lit backdrops in composite work as they provide a more solid colour without requiring the backdrop to be lit separately.

Retroreflective sheeting for road signs is categorized by construction and performance specified by technical standards such as ASTM D4956-11a.; various types give differing levels of retroreflection, effective view angles, and lifespan.

In the case of paint containing glass beads, the paint glues the beads to the surface where retroreflection is required and the beads protrude, their diameter being about twice the thickness of the paint.

Published science and theory proves that the current specifications fail to show a consistency with the coefficient of retroreflection (RA) for Entrance Angles and Observation Angles in relation to the Critical Detection Distance.

Because the function of the eye is to form an image on the retina, an eye focused on a distant object has a focal surface that approximately follows the reflective tapetum lucidum structure, which is the condition required to form a good retroreflection.