It seems like melanopsin cells play some role in vision, though merely a minor one, that may only be relevant if your rods and cone vision is borked for some reason:
ipRGCs were only definitively detected ipRGCs in humans during landmark experiments in 2007 on rodless, coneless humans.[15][16] As had been found in other mammals, the identity of the non-rod non-cone photoreceptor in humans was found to be a ganglion cell in the inner retina. The researchers had tracked down patients with rare diseases wiping out classic rod and cone photoreceptor function but preserving ganglion cell function.[15][16] Despite having no rods or cones the patients continued to exhibit circadian photoentrainment, circadian behavioural patterns, melanopsin suppression, and pupil reactions, with peak spectral sensitivities to environmental and experimental light matching that for the melanopsin photopigment. Their brains could also associate vision with light of this frequency.
It seems like melanopsin cells play some role in vision, though merely a minor one, that may only be relevant if your rods and cone vision is borked for some reason:
The Wiki page on melanopsin containing retinal ganglion cells states: