Which part of the eye is responsible for adjusting the size of the pupil?

How does an eye manage to see objects in dim light and bright light?

The danger signals installed at the top of tall buildings are red in colour. These can be easily seen from a distance because among all other colours, the red light

What is Presbyopia?

$(a)$ Explain the following terms used in relation to defects of vision and corrections provided for them:
$(i)$ Myopia $(ii)$ Astigmatism $(iii)$ Bifocal lenses $(iv)$ Far-sightedness (Hypermetropia).
$(b)$ Describe with a ray diagram how a person with myopia can be helped by spectacles.

$(a)$ What is "power of accommodation of the eye"?
$(b)$ What happens to the image distance when the object being viewed is moved away from the eye?