Create an account
are scattered throughout various regions of the body. These include the sensations of heat, cold, pain, nausea, hunger, thirst, and pressure or touch.
By "reading your mind," we see you already identified it as extrasensory perception or ESP.
secrete sebum onto the eyelids to keep them soft, pliable, and little sticky to trap particles.
protective membrane that covers the exposed surface of the eyeball and protects the exposed eye surface.
produce tears, which are needed for constant cleansing and lubrication and which are spread over the eye surface by blinking.
"watery" humor, bathes the iris, pupil, and lens and fills the anterior and posterior chambers, in the front of the eye.
which maintains eye shape and refracts light rays, is a clear, jellylike fluid that occupies the entire eye cavity behind the lens.
is the outermost layer and is a tough, fibrous tissue that serves as the protective shield we commonly call the "whites of the eye."
the sclera contains a specialized portion called the _________ (window of the eye), which contains no blood vessels and is transparent to allow light rays to pass into the eye.
the middle layer, is a highly vascularized and pgmented region that provides nourishment to the eye.
located in the choroid layer this is the colored portion of the eye that controls the size of the opening (pupil) where light passes into the eye. It is a sphincter, which means it has intrinsic muscles that can relax or contract depending on light conditions.
the third and intermost layer. This area contains the nerve endings that receive and interpret the rays of light.
can alter the shape of the lens, making it thinner or thicker to change the angle of refraction, which allows the focusing of incoming light rays on the retinal area.
combines changes in the size of the pupil and the lens curvature to make sure the image converges in the same place on the retina and therefore is properly focused.
the retina is a delicate membrane that continues posteriorly and narrows to become the ________.
Stye or hordeolum
is an abscess that forms at the base of an eyelash due to infection of a sebaceous gland. Often the result of bacterial infections, _______are red, swollen, and painful.
is an inflammation of the membrane that lines the eye, and is characterized by red swollen eyes. This condition can be caused by a variety of irritants such as fumes or onions. Plathogens such as viruses and bacteria can also be a culprit.
acute infective phase of conjucntivitis; it is a highly contagious form caused by staphylococcus aureus bacteria
is a condition in which the lens loses its flexibility and transparency and light cannot easily pass through the clouded lens.
is caused by increased pressure in the fluid of the eye, which interferes with optic nerve functioning, and can also lead to blindness.
is the reduction or loss of central vision in which peripheral vision is unaffected.
farsightedness that occurs with age, usually between 40 and 45 years. The lens becomes stiff and yellowish.
lazy eye, causes poor vision in one eye because of the abnormal dominance of the other eye, which does most of the work.
one eye is misaligned due to an inablility in the muscles of the eye to coordinate movement with th other eye. cross-eyed appears.
degeneration of the retina can cause difficulty seeing at night or in dim light...often caused by a vitamin A deficiency.
Red-Green Color Blindness
people with this condition can see colors but can't distinguish the difference between red and green.
a neurological assessment...which stands for pupils equal, reactive light and accommodation, can be used to assess brain injury.
Please allow access to your computer’s microphone to use Voice Recording.
Having trouble? Click here for help.
We can’t access your microphone!
Click the icon above to update your browser permissions and try again
Reload the page to try again!Reload
Press Cmd-0 to reset your zoom
Press Ctrl-0 to reset your zoom
It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.
Please upgrade Flash or install Chrome
to use Voice Recording.
For more help, see our troubleshooting page.
Your microphone is muted
For help fixing this issue, see this FAQ.
Star this term
You can study starred terms together