Evolution has tailored the human eye for detecting red, green, blue and yellow in a person’s skin, which reveals areas where that person’s blood is oxygenated, deoxygenated, pooled below the surface or drained. We subconsciously read these skin color cues to perceive each other’s emotions and states of health. Rosy cheeks can suggest good health, for example, while a yellowish hue hints at fear.

Now, researchers have created new glasses, called O2Amps, which they say amplify the wearer’s perception of blood physiology, augmenting millions of years of eye evolution.

Read more: How New ‘Mood Ring’ Glasses Let You See Emotions | LifesLittleMysteries.com.