Visual Optics Practice Test

When light waves travel from one medium to another, their frequency remains constant regardless of the medium they are in. This principle is rooted in the fundamental behavior of waves at the boundary between different materials. Although the speed of light and its wavelength change when moving from a vacuum into other media such as water, high index glass, or ophthalmic crown glass, the frequency, which is determined by the source of the light, does not change.

Consequently, since frequency remains constant across all media, the correct answer underscores that regardless of whether the light is in water, high index glass, or ophthalmic crown glass, the frequency will be the same. This is because the frequency of a light wave is solely a function of its source and is not influenced by the medium through which it travels. Thus, the assertion that frequency would be the same in all media is valid and aligns with the principles of optics.