Asked by: John Radford, High Wycombe
Tears and sweat both have approximately the same salinity, but sweat contains oils and hormones that could irritate the eyes. The sweat that runs into your eyes has also run over your hair and forehead first, so it has had plenty of opportunity to pick up dust and grime along the way.
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Authors
Luis trained as a zoologist, but now works as a science and technology educator. In his spare time he builds 3D-printed robots, in the hope that he will be spared when the revolution inevitably comes.
