Ch 42 Flashcards
Emmetropia
Normal vision
Light rays are bent to focus images precisely on the retina
Myopia
Nearsightedness
People may hold things close to their eyes to see them well
Hyperopia
Farsightedness. People see objects far away better than objects that are close
Light doesn’t get to the retina in this condition
Myopia
Light goes beyond the retina in this condition
Hyperopia
Is associated with aging & results in difficulty with near vision
Presbyopia
A visual distortion caused by an irregularly shaped cornea
Astigmatism
People with ___ errors experience blurred vision. Some seek help for recurrent headaches caused by straining to see clearly
Refractive
Refractive errors are detected with the __ & __
Snellen & jaeger charts
___ usually are corrected with eyeglasses or contact lenses. The lenses bend light rays to compensate for the __
Refractive error x2
Definitions related to low vision refer to the ___
Best corrected visual acuity (BCVA)
Legal term for a BCVA of 20/200 or less even with corrective lenses
Blindness
___ is used to describe BCVA between 20/60 and 20/200 in the better eye with the use of glasses
Visually impaired
BCVA 20/400 to no light perception
Severe loss of visual field, also referred to as blind
___ can be congenital or caused by injury: a high fever that damages the optic nerve
Blindness
Diplopia
Double vision
Described as feeling gritty. There is tearing & the pt usually tries to relieve discomfort by squeezing eyelids closed to help control eye movement & reduce light from entering eye.
Eye trauma
During an eye injury, If the bony orbit is fractured, the eyes may appear __, and the pt has __
Asymmetrical
Diplopia (double vision)
Staining the surface with fluorescein dye identifies a minute foreign body or abrasion to the cornea
Diagnostic finding for eye trauma
Two types of ocular trauma that require quick responses
Chemical burns & foreign objects in the eye
Inflammation of the conjunctiva. Commonly called pinkeye because the inflammation of the subconjunctival blood vessels are more visible causing a reddish or pink appearance
Conjunctivitis
Results from a bacterial, viral or rickettsial infection and can affect one or both eyes
Conjunctivitis
In conjunctivitis the microorganism most often are introduced by ___ transmission, ___ with sources on the fingers, a contaminated face towel or washcloth
Air transmission
Direct contact
Untreated conjunctivitis, especially when caused by ___ and __ can lead to blindness
Neisseria gonorrhoeae
Chlamydia trachomatis