An exact number is impossible to determine, but a reasonable estimate for the number of atoms in an average human eye is in the trillions.
Here's why it's impossible to give a precise number and a breakdown of how the estimate is derived:
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Variability: Eye size varies from person to person. Also, the exact chemical composition (and therefore atomic makeup) will vary slightly depending on age, health, and diet.
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Complexity: The eye is made up of many different types of cells and tissues (cornea, lens, retina, etc.), each with its own unique atomic composition.
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Dynamic Nature: The eye is constantly changing and replenishing cells, so the number of atoms isn't static.
Despite these challenges, we can make an estimation based on available information. The reference suggests:
- Rod cells, which are approximately 2 micrometres in diameter and 100 micrometres long, contain about 30 trillion atoms.
Considering that rod cells are only one component of the eye (albeit a significant one, due to their abundance), and the eye includes a lens, cornea, iris, muscles, and other supporting tissues, a rough estimate of trillions of atoms in the entire eye seems reasonable. It's important to remember this is an informed estimate, not a definitive calculation.
