What it the outer part of the sun, that we see with our eyes, called?

When we look at the sun with our eyes it seems much larger than it actually is. When we use a solar filter we are seeing what the sun actually is.

So, what is the name of the thing the solar filter is eliminating? The larger glare part.

And, why does this happen? Why do we see this light that makes the sun appear bigger and not the smaller circle that is actually the sun?