Special Senses: Vision

Define PRESBYOPIA

"OLD VISION" - Lengthening of the near point accommodation

A test result of 20/15 is better or worse than normal vision

20/15 VISION IS BETTER than normal

Define CATARACTS

A condition causing the lens to become increasingly hard and opaque

Define ACCOMMODATION

Ability of the eye to focus on objects closer than 20 ft

The ability of the eye to focus differently for objects of near vision & 6m (20 feet) is called?

Accommodation

______ is blurred vision caused by irregularities in the curvature of the lens or cornea

Astigmatism

The ______ chart was used in the lab to show irregularities in curvature of the lens/cornea

Astigmatism chart

Predators have what type of vision?

Binocular vision/depth perception

Name one part of the fibrous tunic/layer labeled "A" with the blue tape

Cornea/Sclera

Define HYPEROPIA

Farsightedness. Image is focused behind the retina

name one depolarizing cell found in the sensory layer/tunic

Ganglion cell, bipolar cell, rods, or cones

What is the cause of presbyopia?

Loss of elasticity of the lens over time

Fibers from which eye are found in the left optic tract?

Medial fibers from right eye and laterals fiber from left eye

closer in children and young adults and farther with old age, the _______ is the closest distance an object can be focused on clearly

Near point of accommodation

Define MYOPIA

Nearsightedness. Image is focused in front of retina

the ______ chart is used to measure visual acuity

Snellen Chart

The Snellen chart was used to test _____

Visual acuity

The branched optic radiations will terminate in which region of the brain?

Visual cortex

what do the tarsal glands produce?

an oily substance

name one part of the vascular tunic/layer labeled "A" with the blue tape

choroid

the _____ lens is used to correct the myopic/nearsighted eye

concave

which specific type of lens is used to correct myopia?

concave lens

the photoreceptor cells called _____ are responsible for color vision

cones

what is the medial rotation of the eyes called?

convergence

The _____ lens is used to correct the hyperopic/farsighted eye

convex

Which specific type of lens is used to correct hyperopia?

convex lens

what are the tears comprised of?

dilute salt solution with lysozymes

What is the function of the ciliary glands?

eyeball lubrication

What do the extrinsic muscles allow the eye to do?

eyeball movement, follow a moving object

what is the function of the lacrimal sac?

fills & stores tears

What eye disorder is caused by compression of retina/optic nerve?

glaucoma

Name one of the non-depolarizing supporting cells found in the retina

horizontal cells

What is a sty?

inflammation of the ciliary (sweat) glands or a small oil gland

what is conjunctivitis?

inflammation of the conjunctiva

Name one of the 2 groups of muscles responsible for eye reflexes

intrinsic/extrinsic muscles

What is the function of the lysozyme?

kill bacteria

Name of constituent of the lacrimal apparatus

lacrimal sac

Fibers from which eye are found in the left optic nerve?

left eye

Fibers from which eye are found in the optic chiasma

median fibers from the left and right eyes

prey tend to have what type of vision?

panoramic

the _____ reflex is observed by sudden illumination of the retina by bright light causing the pupil to constrict in direct proportion to light intensity

photopupillary

what is the function of the scleral venous sinus?

reabsorption of aqueous humor

what accompanies conjunctivitis in the eyeball?

redness

what is the bending of light upon passing from one substance to another called?

refraction

light bending power of the cornea, lens, or vitreous humor is called its

refractive index

in the convergence reflex test done in the lab, what was the reaction of looking and focusing at a distant object and then focusing at a very close object by the eyes?

regular eye movement, then medial eye movement to view close object

The ____ is the part of the eye that is examined when using the opthalmascope

retina

name one part of the sensory tunic/layer labeled A with the blue tape

retina

fibers from which eye is found in the right optic nerve?

right eye

the photoreceptor cells called _____ are responsible for dim light vision

rods

what do the lacrimal glands produce?

tears

A test result of 20/40 is better or worse than normal vision

worse than normal vision

______ is the general name of the involuntary muscles that are responsible for changes in both the lens curvature and pupillary size

Intrinsic muscles

_______ is the specific name of the color plates used to test for color blindness in lab

Ishihara Color Plates

optic tract fibers will synapse with what part of the brain?

Lateral geniculate body of the thalamus

What causes glaucoma

Optic nerve due to lack of drainage of the aqueous fluid

fibers/axons from the lateral geniculate nucleus will branch into the

Optic radiation

In the accommodation pupillary reflex test done in the lab, what was the reaction of looking and focusing at a distant object and then focusing at a very close object by the pupils?

Pupil dilation & constriction