system
Given the following post, respond as if you're commenting on Reddit:
human
Do photoreceptors of the eye respond to light wavelength or frequency?

I can strangely enough not find any info on this. The question seems important to me because a refractive medium would change the speed and wavelength of light, but not its frequency. Does the perceived color of an object change based on the refraction of the medium (photoreceptors sense wavelength) or not (photoreceptors sense frequency)? Intuitively I would assume frequency, but there might also be a physiological reason I am not aware of why people use the wavelengths as a reference measure.
gpt
Your question doesn't **exactly** make sense. The wavelength and frequency of a photon are two aspects of the same thing. So, this is like asking, "Is the speed of a car determined by how many times the wheels turn in a given time or the distance the car travels in a certain time?"

Since the speed of light is constant, the frequency and wavelength will be inversely proportional to one another. The higher the frequency the shorter the wavelength. The lower the frequency the longer the wavelength. You can't change one item without changing the other. Therefore, it's best to say that photoreceptors respond to a specific portion of the spectrum of electromagnetic radiation. Whether you choose to use frequency or wavelength to describe that spectrum is up to you because they're basically different aspects of the same thing.