DISORDER OF THE LENS: CATARACT Flashcards
an eyeball cut in half (cross-section), showing the lens and the passage of light through it from the object ahead to the focus on the retina
Crystalline lens
also called lens
Crystalline lens
Properties of Crystalline Lens
-Biconvex
-Relatively Acellular
-Optically Transparent Intraocular Structure
-Suspended behind the iris
-Serves to transmit light to the retina with minimal scattering
Composition of Crystalline Lens
-Collagen
-Proteins (60% of the lens weight)
-unusual elongated cells
Blood Supply of Crystalline Lens
None.
give nutrients to the crystalline lens and remove waste products
Aqueous Humour
The relaxation and contraction of ciliary muscles surrounding it, thereby changing the focal distance to the retina and bringing the image widely varying distance into sharp focusnof the retina
Accommodation
The relaxation and contraction of ciliary muscles surrounding it, thereby changing the focal distance to the retina and bringing the image widely varying distance into sharp focusnl of the retina
Accommodation
attaches the lens to the ciliary body, which holds the lens in the position and determines its degree of accommodation
Zonular Fiber (Suspensory Ligaments)
attaches the lens to the ciliary body, which holds the lens in the position and determines its degree of accommodation
Zonular Fiber (Suspensory Ligaments)
a condition wherein the accommodation gradually declines with age, often requiring correction
Presbyopia
a condition wherein the accommodation gradually declines with age, often requiring correction
Presbyopia
True Or False: the lens is flatter on its anterior side than on its posterior side
True
Four Structures.of Crystalline Lens
-Capsule
-Epithelium
-Cortex
-Nucleus
a dense, cloudiness that forms in the normal crystal-clear ocular lens which causes visual loss when it is located on the visual lens
Cataract
