Eli5 how does a pupil dilating reduce or increase intensity of light without effecting peripheral vision?

Question

I understand that a pupil getting smaller lets less light in so in bright settings it reduces the total amount of light hitting the eye but why? Wouldn’t the intensity of light be the same? How does this not effect peripheral vision if the hole that we see from gets smaller?

In: 1

Answer 1

Because of the lens. Light from a point (for instance the top of a tree) scatters in all directions, but the lens focuses it to a single point on your retina. Without the lens, your field of vision would be reduced as you suggested to whatever light could pass through your pupil and hit the retina. (it would also be very blurry)