How come our tears taste salty but don’t hurt our eyes but actual saltwater (like in the ocean) does?
In: Biology
Salinity (or concentration of salt).
Tears, saline solution, saltwater pool: 3500 ppm
Ocean: 35000 ppm
Higher concentration of salt I assume.. like the human body’s PH level is set between 7.35 and 7.45 for a normal healthy person.. the salt in your tears is much less than ocean water.. like an IV or normal saline is .9% NaCl.. ocean water is in the ballpark of 3.5% of mostly salt amongst other minerals. That’s way higher than our bodies thus burning your eyes. Like saline eye drops also have salt in them however it is in balance with our bodies PH, thus not burning your eyes.
It is due to the concentration. Sea water is a highly concentrated solution of salt (3.5%) whereas tears probably under 1%.
This is also one of the reasons why you cannot drink seawater to reduce your thirst.
Its a question of concentration. The sea is saltier. Whenever you get a gradient in salt like this water moves from one side to the other to try and balance out. Very bad for living tissue and leads to things like salt preservation of fish/meat/veg and saltwater/freshwater species of marine life
Saltwater has more salt than tears. If you drop your eyes with the same concentration of salt as tears it won’t sting. If it’s lower or higher it’ll be uncomfortable.
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