Lens (vision)

The lens or crystalline lens is a component of the eye. In concert with the cornea, it refracts light, focussing it onto the retina.

Related Topics:
Eye - Cornea - Light - Focus - Retina

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

The lens is clear and flexible; its curvature is controlled by ciliary muscles. By changing the curvature of the lens, one can focus the eye on objects at different distances from it. This process is called accommodation.

Related Topics:
Ciliary muscle - Accommodation

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

The lens is about 5 mm wide and has a diameter of about 9 mm for an adult human (though these figures can vary). The lens is included into the capsular bag, maintained by the zonules of Zinn.

Related Topics:
Capsular bag - Zonules of Zinn

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

During the fetal stage, the development of the lens is aided by the hyaloid artery. In adults, the lens depends entirely upon the aqueous and vitreous humors for nourishment.

Related Topics:
Fetal - Hyaloid artery - Aqueous - Vitreous

~ ~ ~ ~ ~ ~ ~ ~ ~ ~