Hmm,
I have 4 red differant brands of red dots (on slug guns and ML), love them.
1st) eastern woods - all shoots are under 90 yds, most 10-60 from a climber.

Red dots do not "gather light", fact is to use one as intended, You do not "look through" the scope.
When I spot a deer, I keep both eyes on it and raise the gun up never taking My eyes off the deer, when the gun is shouldered both eyes are open and the scope body "dissapears" and a red dot is "imposed" on my "view".
Where ever that red dot is, that is where the bullit is going.

That said, The BSA red dots 3MOA(cheap) are not bright enough for snow or mid day sun in the open.
The Gilmore 8MOA is kinda bright and is on My goose gun
The Burris speed dot is perfect- lowest setting is no problem at "dark:30", brightest setting is good enough for snow.

Now My red dots are mounted forward, so they are 4-6 inches from My eye,
But yeah, if You have one eye closed and the shooting eye half way down the scope tube, the dot may block out the target, but thats not how they are designed to be used.

Slack