5 errors of refraction Željka burčul mentor: a. Žmegač horvat

5

ERRORS OF

REFRACTION

Željka Burčul Mentor: A. Žmegač

Horvat

What are we going to talk about????

myopia

astigmatism

conjunctivits

hyperopia

blindness

glaucoma

cataract

presbyopia

MYOPIA

myein = “to shut” (Greek) ops = eye (Greek) nearsightedness

condition in which close objects are seen clearly, but objects farther away appear blurred

not inherited but caused by excessive reading and other close work

first occurs at school-age

Symptoms:

blurred vision difficulty seeing distant objects frowns holding books or objects very close to the face sitting at the front of a classroom or theater or close

to the TV or computer no interest in sports or other activities that require

good distance vision frequent headaches

HYPEROPIA

farsightedness, longsightedness or

hypermetriopia

condition in

which distant objects are

usually seen clearly,

but close ones appear

blurred

inherited

Symptoms:

difficulty seeing up close blurred distance vision (occurs with higher

amounts of hyperopia) eye fatigue when reading eyestrain (headaches,

pulling sensation, burning)

ASTIGMATISM

corneal irregularity that causes multiple focal points and blurred picture

Causes:

heredity pressure of the eyelids on the cornea incorrect posture or increased usage of eyes

for close work any eye injury

Symptoms:

headaches, fatigue, eyestrain and blurred vision at all distances

difficulty focusing on printed words and lines

PRESBYOPIA

˝short arm syndrome˝ ,

age-related farsightedness

condition in which an

eldery person’s sight fails

gradually

Causes:

hardening and loss of flexibility of the lens two theories trauma occupation lifestyle

Symptoms:

blurred vision at a normal reading distance need to hold reading materials at arm's length headaches, eyestrain and fatigue after near work

How are these conditions diagnosed?

How are they treated?

eyeglasses

contact lenses

laser and other refractive surgery

procedures

References:

http://en.wikipedia.org/wiki/ http://www.allaboutvision.com/conditions/ www.bausch.com/... www.medicina.hr http://images.google.hr