Question: how many molecules are there in one eye?

Priya Hari answered on 21 Jun 2015:

This is quite a difficult question to get a proper accurate answer, especially considering everyone has different sized eyes and not every single molecule has been discovered.

But, we can make some assumptions based on what we already know. Our cells are 70% water, and since water molecules are so small, they make up 90% of the molecules in a cell. The other 20% cell is made up proteins and the remaining 10% will be fats, carbohydrates and nucleic acids. There are about 7,900,000,000 protein molecules in a liver cell. It is likely to be something similar for an eye cell. There are about 6 million cone cells and 100 million rod cells in eyes, but our eyes are made up of other parts such as the cornea, lens and optic nerve. So in one eye there might be something like 2 x 10^18 molecules! -basically an extremely big number with a lot of zeros. (This is a complete estimate based on data I found on the internet, so don’t quote me on it!)