Medications, trauma, and medical conditions can cause miosis or constricted pupils. Seek emergency help if you experience signs of a stroke, like confusion or trouble speaking. A healthcare provider ...

Even Charles Darwin was puzzled by the evolution of the vertebrate eye. New research suggests that it traces back to a cyclopean invertebrate with a single eye atop the head. By Carl Zimmer Look at ...

Hold a pencil upright in front of your face. Close one eye, look at the pencil, then open that eye, and close the other. Did you notice that your view of the pencil shifted slightly when you looked ...