The usage of "as" and "while" as conjunctions
Both of them means that something happens at the same time as something else happens. So do they differ in the least?

Here's an example:

- I avoid looking at anybody as I take tiny spoonfuls of fish soup

- I avoid looking at anybody while I take tiny spoonfuls of fish soup

Question

The usage of "as" and "while" as conjunctions
Both of them means that something happens at the same time as something else happens. So do they differ in the least?

Here's an example:

- I avoid looking at anybody as I take tiny spoonfuls of fish soup

- I avoid looking at anybody while I take tiny spoonfuls of fish soup

Answer

In these two contexts there's no difference in meaning, and they can reasonably be swapped.

Answer

as and while can both be used to talk about two longer actions happening at the same time. But we must be careful AS the conjunction 'AS' can mean 'because' and sometimes it can be confusing. 
you can study the conjunction 'as' here: http://www.oxfordlearnersdictionaries.com/definition/english/as_3