Question

whats the best way to check debris has been removed from the eye?
examining the eye
examining the towel
examining the solution in the return basin
examining the area around the eye

Explanation:

To confirm debris is fully removed from the eye, the only direct way to verify the eye itself is clear is to examine the eye. Checking surrounding areas, towels, or rinse solution only indicates debris may have been displaced, but not that the eye is free of it.

Answer:

Examining the eye