What is the complementary color of red?

$A$ person cannot read a book at distances less than $50\, cm$. Name the defect of vision he is suffering from. How can it be corrected? Draw ray diagrams to show the image formation
$(i)$ by defective eye and
$(ii)$ after using corrective lens.

Which of the following relationships regarding the wavelengths $\lambda$ of different colors of light is correct?

Which color of light is scattered the most due to the atmosphere?

For a person suffering from myopia,the image of the object is formed in front of the retina.

Name the outermost layer of the eye. What is its function?