COA exam study Questions and Answers
(JCAHPO)
levator palpebrae superioris - answer Muscle that elevates the lid
Sclera - answer white opaque fibrous shell, main purpose is to protect eye
Cornea - answer A transparent convex covering which protects the eye and helps focus light rays onto the
retina and the back of the eye
meibomian glands - answer The largest oil-secreting glands, which are embedded in the posterior connective
tissue substance of the lids
Corneal Epithelium - answer Part of the cornea that is usually injured by superficial abrasions or small
foreign bodies. Is 5-7 cells thick and is composed of nonkeratinized stratified squamous cells.
Corneal Epithelium - answer Part of the cornea that regenerates rapidly and heals without leaving a scar.
Bowman's membrane - answer Consists of randomly oriented collagen fibrils of greater periodicity then the
underlaying stroma.
Bowman's membrane - answer Acellular layer of cornea that has no regenerative capabilities. Function is
unclear.
Stroma - answer Layer just under Bowman's membrane. Accounts for 90% of corneal thickness and is
composed of 78% water.
Descemet's membrane - answer Layer of the cornea that is composed of type III collagen, forms the basement
membrane of epithelial cells.
Endothelium - answer 4-6um thick layer of the cornea made of 500,000 cells that maintains corneal
deturgescence. No regenerative abilities.
Limbus - answer The gray, semitransparent area which demarcates the junction of the cornea and sclera.
Cornea is completely nourished by - answer 3 sources: A plexus of fine capillaries at the limbus, the tear film,
and the aqueous humor.
Vitreous - answer jelly like structure, thick and viscous, that occupies the vitreous chamber in the posterior
concavity of the globe.
Lens - answer A transparent biconvex structure situated between the iris and the vitreous.
Iris - answer The most anterior structure of the uveal tract.
Uveal tract - answer Consists of three structures: iris, ciliary body, and choroid.
Retina - answer The innermost coat of the eye, formed of sensitive nerve elements and connected to the optic
nerve.
A-scan - answer An ultrasound technique to determine the axial length of the eye to calculate the intraocular
lens power required.
Abbe number - answer An indication of optical quality. Number is inversely proportional to the chromic
(JCAHPO)
levator palpebrae superioris - answer Muscle that elevates the lid
Sclera - answer white opaque fibrous shell, main purpose is to protect eye
Cornea - answer A transparent convex covering which protects the eye and helps focus light rays onto the
retina and the back of the eye
meibomian glands - answer The largest oil-secreting glands, which are embedded in the posterior connective
tissue substance of the lids
Corneal Epithelium - answer Part of the cornea that is usually injured by superficial abrasions or small
foreign bodies. Is 5-7 cells thick and is composed of nonkeratinized stratified squamous cells.
Corneal Epithelium - answer Part of the cornea that regenerates rapidly and heals without leaving a scar.
Bowman's membrane - answer Consists of randomly oriented collagen fibrils of greater periodicity then the
underlaying stroma.
Bowman's membrane - answer Acellular layer of cornea that has no regenerative capabilities. Function is
unclear.
Stroma - answer Layer just under Bowman's membrane. Accounts for 90% of corneal thickness and is
composed of 78% water.
Descemet's membrane - answer Layer of the cornea that is composed of type III collagen, forms the basement
membrane of epithelial cells.
Endothelium - answer 4-6um thick layer of the cornea made of 500,000 cells that maintains corneal
deturgescence. No regenerative abilities.
Limbus - answer The gray, semitransparent area which demarcates the junction of the cornea and sclera.
Cornea is completely nourished by - answer 3 sources: A plexus of fine capillaries at the limbus, the tear film,
and the aqueous humor.
Vitreous - answer jelly like structure, thick and viscous, that occupies the vitreous chamber in the posterior
concavity of the globe.
Lens - answer A transparent biconvex structure situated between the iris and the vitreous.
Iris - answer The most anterior structure of the uveal tract.
Uveal tract - answer Consists of three structures: iris, ciliary body, and choroid.
Retina - answer The innermost coat of the eye, formed of sensitive nerve elements and connected to the optic
nerve.
A-scan - answer An ultrasound technique to determine the axial length of the eye to calculate the intraocular
lens power required.
Abbe number - answer An indication of optical quality. Number is inversely proportional to the chromic
