Question

Apposition image in eye of insects is formed in ..................

• A. Dim light
• B. Bright light
• C. Dark light
• D. None of the above

Answer 1

The correct option is B Bright light

The compound type of eye is found in arthropods. A compound eye has a network like appearance. They consists of minute lenses called ommatidia. The eye can form either apposition images or superposition images with the help of the lenses. In the case of an apposition eye, each ommatidium focuses only rays coming from the bright light that are almost parallel to its long axis. The image of the whole results from a combination of these part images. In superposition eye, the sensory cells of an ommatidium can pick up light from a large part of the visual field. The image received may overlap those received. The superposition image thus gains in brightness but loses in sharpness compared with the apposition image. Diurnal insects have apposition images as these kind of images are formed in the bright light.

Thus, the correct answer is option B.