Which of the following best describes the power of accommodation of the human eye?
The ability of the eye lens to change its focal length to focus on objects at different distances
The distance between the eye lens and the retina is fixed, so a sharp image of both near and distant objects can only be formed if the lens itself changes its converging power.
The ciliary muscles do this: when they contract the lens becomes thicker and its focal length shortens for near objects, and when they relax the lens thins and its focal length lengthens for distant objects. This adjustment of focal length is called the power of accommodation.
Changing pupil size only controls how much light enters, and eyelid or eyeball movement plays no part in focusing an image on the retina.
Hence, the answer is The ability of the eye lens to change its focal length to focus on objects at different distances.
Similar Questions
A student places an object 20 cm in front of a concave mirror with a focal length of 10 cm, using the sign convention for spherical mirrors. What is the correct value and sign for the image distance?
A student notices that the image formed by a lens is virtual, upright, and larger than the object. Which lens and object position is responsible for this observation?
The measure of an image's clarity is called _________, whereas _________ is the brightness difference between object parts.
What is the primary reason stars appear to twinkle in the night sky as seen from Earth?
A 3 cm tall object is placed 9 cm in front of a concave lens with focal length 6 cm. What is the approximate height of the image formed?
When an object is placed at 2F1 of a convex lens, where is the image formed?
Which defect of vision is caused by the eye's lens focusing images in front of the retina, making distant objects appear blurry, and can be corrected using a concave lens?
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Which of the following statements related to dispersion are true?
(1) Red light bends the most when passing through a glass prism.
(2) The angle of deviation is the same for all colours.
(3) Dispersion is one of the phenomena responsible for the formation of a rainbow.
(4) The speed of light decreases as the light goes from air into the prism.
Important Questions from Optics
Who was the first one to use a glass prism to obtain the spectrum of sunlight?
Twinkling of stars is due to:
In which a convex mirror is used?
A. Rear View mirrors in vehicles
B. Glass windows
C. Makeup Mirror
D. Kaleidoscope
An object is placed 10 cm in front of a lens. The image formed is real, inverted and of same size as the object. What is the focal length and nature of the lens?
The power of a lens is -2.5 D. The type of lens and its focal length are respectively:
