Calling this a "flaw" is dubious. It's merely a
structure that causes no problem because
the brain fills in the missing info. Are there
better ways to construct an eye & the
brain that interprets light entering the eye?
That would be a tough argument to make.
Vision is a complex relationship between
light entering the eye, what the eye sends
down the optic nerve, & what the brain does
with that info for us to experience vision.
They're all different versions of reality in our
visible world. We "see" (ie, experience) the
brain's highly processed version of reality.
It's a more useful version than the mere light
entering the eye. It's an efficient system that
avoids the need for far more brain processing
power.
Some background.
What we see in the periphery, just outside the direct focus of the eye, may sometimes be a visual illusion, research shows.
www.psychologicalscience.org