The amazing eye

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I wonder...

The amazing eye

Why is the retina set up in a way that requires light to travel across several different cell layers before landing on the photoreceptors? Why aren’t the photoreceptors in front of all the other cells that just transmit the electrical signal created by the photoreceptor rods and cones? Seems like a poor design…

I drew a picture to explain… but here’s the gist:

The location of the photoreceptors is determined by the location of the retinal pigment epithelium. This epithelium needs to be located at the back of the retina because light cannot pass through it. If we wanted the photoreceptors in from of the retina so that light had more direct access, the photoreceptors would need to be a completely different design – embedded into the epithelium.  Not only that, but besides not allowing light to pass, the epithelium also absorbs excess light (via melanin – the same pigment…

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