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