Which cranial nerve controls accommodation?

cranial nerve III
Another reflex associated with the cranial nerve III is the accommodation reflex. At rest, the lens is thin, to allow the eye to focus on far objects. To focus on near objects, the lens must thicken, by a process called accommodation, as described in Chapter 7.

What part of the eye is responsible for accommodation?

ciliary muscles
The ciliary muscles, responsible for accommodation of the eye, are usually at rest. When at rest, parallel light rays that form distant objects converge onto the retina, giving you a sharp and clear view of the object.

Which cranial nerves are responsible for the pupillary reflex to light and accommodation?

The pupillary light reflex requires CN II, CN III, and central brain stem connections. Light shined in one eye stimulates retinal photoreceptors, and subsequently retinal ganglion cells, whose axons travel through the optic nerve, chiasm, and tract to terminate in the pretectum (pretectal nucleus).

What does the 3rd cranial nerve control?

The oculomotor nerve is the third cranial nerve (CN III). It allows movement of the eye muscles, constriction of the pupil, focusing the eyes and the position of the upper eyelid. Cranial nerve III works with other cranial nerves to control eye movements and support sensory functioning.

How do you find accommodation reflex?

Testing for the accommodation reflex follows nicely on from eye movements. Ask the patient to keep focusing on the tip of your index finger and slowly move it towards them, aiming for the tip of their nose. You need to be watching their pupils to make sure you see them constrict as your finger gets closer.

What is the mechanism of accommodation?

According to the classical view, as described by Helmholtz,9 accommodation occurs by contraction (forward and inward movement) of the ciliary muscle and relaxation of the zonules that attach the ciliary body to the lens; as a result, the lens thickens and becomes more steeply curved, increasing the refractive power of …

What does accommodation mean in eyes?

Accommodation of the eye refers to the act of physiologically adjusting crystalline lens elements to alter the refractive power and bring objects that are closer to the eye into sharp focus.

What happens in accommodation reflex?

During the accommodation reflex, the pupil constricts to increase the depth of focus of the eye by blocking the light scattered by the periphery of the cornea. The lens then increases its curvature to become more biconvex, thus increasing refractive power.