January 4, 2019

Why do I cry?

That depends on the kind of crying you’re talking about. Our eyes produce tears of three types… Basal tears flow constantly to keep our eyes from […]
January 4, 2019

Why do my eyes sting when I swim in the ocean but not when I cry?

Because sea water contains about three times more salt than your tears. The higher concentration of salt can cause a mild stinging in your eyes even […]
January 4, 2019

Why are my tears salty?

Sodium chloride – the most common type of salt – is in all your body’s fluids: blood, sweat, and (yep) tears. Your tears contain a little […]
January 4, 2019

Why the chickens have terrible night vision?

Chickens have terrible night vision, but they’re capable of seeing colors – including vibrantly purple ultraviolet colors – that humans cannot. Researchers think chickens and other […]