Our eyes are extremely light sensitive and forward the captured light impulses to our brain. Does this mean, we see with our eyes or with our brain?
The answer is simple. In case our eyes would get "connected" to our brain upside down, our brain would adapt to see things again in the right way after some time. Therefore, our brain is the important organ which "assembles an image" for us.
Many vision problems can be "neutralized" by the brain such as forms of astigmatism and refractive errors on one eye only can be balanced by the brain which will provide you with a sharp image generated out of the available information. For stronger forms of astigmatism we then require vision correction such as spectacles or contact lenses.