As light enters the eye, it reaches the photoreceptors at the "base" of the retina, which then pass that signal to the bipolar and ganglionic neurons -- the latter of which send the signal outside of the eye via their axons (collectively forming the optic nerve).
- The exit point of the optic nerve is sometimes referred to as the "blind spot" because there are no photoreceptors present there and therefore no sensory information is gathered.
Now, I know photoreceptors exist everywhere else along the retina, so it's not surprising that we perceive vision from the otherwise broadly distributed photoreceptors.
However, my question: why do the blood vessels associated with the superficial vascular plexus (which exist between incoming light and the rest of the retina) not obstruct our vision?
- More broadly, I guess of interest is: why none of the vascular plexuses (or cell structures of the bipolar and ganglionic neurons for that matter) obstruct our vision despite existing between the photoreceptors and incoming light?
Sources: LEFT: Figure 1 from Zhongjie et al (2020) ; RIGHT: Figure 5 from Selvam et al (2018)
Fu, Z., Sun, Y., Cakir, B., Tomita, Y., Huang, S., Wang, Z., Liu, C.H., S Cho, S., Britton, W., S Kern, T. and Antonetti, D.A., 2020. Targeting neurovascular interaction in retinal disorders. International journal of molecular sciences, 21(4), p1503
Selvam, S., Kumar, T. and Fruttiger, M., 2018. Retinal vasculature development in health and disease. Progress in retinal and eye research, 63, pp.1-19.