I believe anything dust-sized, microscopic, and smaller.
The human eye can typically see objects as small as 0.1 millimeters, which is about the width of a human hair.
An atom is very small the human eye can not see an atom that is what makes it small.
microeconomist
A microbiologist.
A microbiologist.
The human eye, while small, is amazingly complex. An eye diagram is a useful reference for doctors, ophthalmologists, opticians, and the scientifically curious.
You can see anything small with it that you can't see with the human eye
A stethoscope
A microbiologist.
A microbiologist would study living organisms that are too small to see with the naked human eye. They study microorganisms such as bacteria, viruses, fungi, and protozoa.
If you mean, "which wavelengths of light can the human eye detect," the human eye can see wavelengths from about 390 to 700 nanometers.
Yes, it his slightly blue but it appears colorless to the human eye when in small quantities.