Question

Write down the names of the specified parts of the human eye.
(1) A dark muscular diaphragm that controls the pupil.
(2) The screen where the image is formed by the eye lens.

Answer 1

Hint
Human eye operates similarly as a camera does. It is a sense organ that works to form an image that is carried to the brain through the optic nerve in the form of electric impulses. Parts of the eye include the iris, pupil, cornea, retina, sclera, lens, and conjunctiva.

Complete step by step answer
(1) The part of the human eye that is the dark muscular diaphragm that controls the pupil is referred to as iris.
Iris is a flat, thin, and ring-shaped structure in the eye that is present behind the cornea and consists of a circular opening called a pupil that helps in focusing the right amount of light inside the eye. The amount and the kind of pigmentation are responsible for the colour of the eye.
(2) The screen where the image is formed by the eye lens is referred to as the retina of the eye. The retina is the thin layer of tissue that is sensitive to light. The function of the retina is to receive the amount of the light focused by the eye lens and convert it into chemical energy thereby activating the nerves that send the neural signals to the higher regions of the brain. This results in the visual recognition of the image thus formed by the eye lens.
Therefore, iris and retina are the required answers.

Note
Iris is present in the eye in most mammals and birds along with humans. Similarly, the retina is present in all vertebrates including humans.