Find all objects currently colliding with trigger

Lets say I have a simple sphere collider that I am using as a trigger for an enemies vision radius. Is there a way to quickly get an array or list of all the colliders currently colliding with that trigger or within it?

Currently the only way I can think to do this would be to maintain my own list on the object using OnTriggerEnter and OnTriggerExit. However I am assuming I have simply missed a function that does exactly this when I looked through the script reference for it. I also could use Physics.overlapsphere however that would result in me having to place hard coded values within the script and I would much prefer to simply be able to call the trigger sphere collider I already have attached to the object and then acquire a list or array of colliders to work with.

Thank you in advance for any help.

I also could use Physics.overlapsphere however that would result in me having to place hard coded values within the script

Not necessarily: you could access your trigger collider to use its position and radius as parameters for the call.

Like BY0LOG1C said, though, you may want to consider using the enter/exit functions provided by the trigger itself.