Eyes of the nocturnal birds have large cornea and a large pupil. How does this structure help them?

Nocturnal birds are those birds which have the ability to see at night. As these birds have the ability to see at night it implies that they require a large amount of light to enter into their eyes so that they could see in the dim light. This is the reason why nocturnal birds have large cornea and a large pupil so that a large amount of light could enter into their eyes to enhance their night vision ability.