Editing Index-matching material (section)

In [[optics]], an '''index-matching material''' is a substance, usually a liquid, cement (adhesive), or [[gel]], which has an [[index of refraction]] that closely approximates that of another object (such as a lens, material, fiber-optic, etc.).

When two substances with the same index are in contact, light passes from one to the other with neither [[fresnel reflection|reflection]] nor [[refraction]]. As such, they are used for various purposes in science, engineering, and art.

For example, in a popular home experiment, a glass rod is made almost invisible by immersing it in an index-matched transparent fluid such as [[mineral spirits]].<ref>[http://www.optics4kids.org/home/content/classroom-activities/medium/lose-a-glass-in-a-glass/ Optics For Kids - "Lose a glass in a glass" home experiment]</ref>