How particle of solution can't be seen with naked eye?

Particles in a solution, such as ions or small molecules, are typically at the molecular or atomic scale, often less than 1 nanometer in size. This size is far below the resolution limit of the human eye, which can generally only detect objects down to about 0.1 millimeters. Additionally, these particles are uniformly dispersed and do not scatter light effectively, making them invisible to the naked eye. Hence, solutions appear clear or colored, but their individual particles remain undetectable.