Chickens can see only in bright light. What type of cells is present in their retina?

What is the difference in the colours of the Sun observed during sunrise/sunset and at noon? Provide an explanation for each.

Explain the phenomenon of dispersion of white light through a glass prism,using a suitable ray diagram.

$(i)$ What is meant by dispersion of white light? Draw a diagram to show the dispersion of white light by a glass prism.
$(ii)$ Light of two colours $A$ and $B$ pass through a prism. $A$ deviates more than $B$ from its path of incidence. Which colour has a higher speed in the prism?

Which phenomenon is responsible for the blue color of the clear sky?

$A$ person needs a lens of power $-0.5 \text{ D}$ for correcting his distant vision. For correcting his near vision,he needs a lens of power $+1.5 \text{ D}$. What is the focal length of the lens required for correcting his $(i)$ distant vision,$(ii)$ near vision?