Smaller apertures in optical systems like the eye have a greater depth of field. This means that it is easier to focus when there is more light. As we get olde

Smaller apertures in optical systems like the eye have a greater depth of field. This means that it is easier to focus when there is more light. As we get older the lenses in our eyes become less flexible and it is harder for our eyes to focus on closer subjects. This is true even for children when compared to infants.