naked eye
1
the human eye unaided by any optical device, used for observing objects and details directly
- The stars are visible to the naked eye on a clear night sky.
- With the naked eye, you can see the texture and color of the fabric.
- Microorganisms cannot be seen with the naked eye; you need a microscope.
- He inspected the machinery with the naked eye before using diagnostic tools.
- The mountain range stretched out far beyond what could be discerned with the naked eye.