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Physics Rod cells in the retina of the eye detect light using a photopigment called rhodopsin.? - spectra eye insurance

Staffs recognize the retina of the eye to light with a pigment called rhodopsin. 1.8 eV is the lower photon, which can trigger a response in rhodopsin.What, the maximum wavelength of electromagnetic radiation that can cause a transition? In nm
Which part of the spectrum is it?