Term
when you incease the index of a lens do you change the speed of light traveling through the lens medium |
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Definition
yes the speed of light will decrease |
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Term
what part of the retain is concerned with visual acuity and color perception |
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Definition
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Term
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Definition
normal eye (eye with no reft error )light focus on the retain |
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Term
directing the visual axis of the eyes to near point is |
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Definition
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Term
it is not recommended to heat treat lenses stronger than |
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Definition
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Term
it would be necessary to ? the lens to mount it in a nylon suspension type frame |
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Definition
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Term
warpage may be removed from a plastic lens by placing the frame and the lens in a |
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Definition
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Term
the RX of patient is OU -9.25 -0.75X180 what are the recommended precautions to take in prder ti insure proper fitting |
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Definition
monoculat PD and OCHT measurements |
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Term
which of the following is not a cause of one lens being higher than the other |
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Definition
a bent earpiece
a bend in the temple shaft
a skewed bridge
one ear higher than the other
ALL OF THEM ARE POSSIBLE CAUSE |
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Term
if the wearer complains of the bifocal line being some what in his way when driving the problem may be alleviated by decreasing the distance between pads |
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Definition
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Term
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Definition
a triangle representing the main supporting point for a pair of glasses |
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Term
if the eyelashes rub the lenses the fitter should |
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Definition
increase the vertex distance |
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Term
if the wearer complains that the glasses feel snug but still slip down the nose one likely cause is that |
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Definition
pressure is being applied by the temple shafts anterior to the ear |
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Term
when viewing the wearer from the front it is discovered that the frame sits too far to the left (wearer's right )on the wearer's face .this could be cause by ? |
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Definition
both pads shifted to wearer's left or
the wearer's nose being crooked |
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Term
if both nose pads press the nose or indent too much what is probably not a possible cause |
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Definition
temple spread is not even |
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Term
to eliminate a gap between the lens and a metal eyewire ,the best alternative is to |
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Definition
place a strip of lens liner at the point exactly opposite the gap |
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Term
which factor is nonessential in dispensing the progressive add lens |
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Definition
a good pantoscopic angel
short vertex distance
large b dimension
good monocular lens centration
ALL OF THE ABOVE ARE ESSENTIAL |
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Term
what is the geometrical center distance of frame marked A 50/DBL 17 |
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Definition
add the a with the dbl 50+17=69
that is the geometrical center distance |
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Term
the larger the frame difference ? the lens shape |
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Definition
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Term
if a frame dimensions are A 50 and the ED 55 with frame difference of 8 ,what is the B |
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Definition
take the A 50 mearsurement - 8 the difference and the is the B
ANSRW IS 42 |
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Term
a frame is marked 52/18 the lens shape is round ,what is the effective diameter of the lens ? |
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Definition
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Term
which error is of no consequence in verifying correctness of frame and lenses |
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Definition
air space between lens and frame
chips in the lens edge between bevel and lens surface
distortion (unevenness)in lens edge between bevel lens surface
ALL OF THE ABOVE ARE OF CONSEQUENCE |
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Term
when the wearer's PD is less than the frame FD |
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Definition
positive face form is required |
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Term
the new bifocal wearer must |
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Definition
drop the eye to read a book |
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Term
when the frame front is tested for four point touch but only touches in the two temporal eyesores the frame |
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Definition
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Term
which of following errors will not be detected by a four point touch test |
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Definition
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Term
it is unnecessary to use heat in adjusting a zly frame when |
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Definition
changing the pantoscopic angel |
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Term
if the pad arms bent up and the pads re-aligned this adjustment will |
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Definition
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Term
what is the final step in fiiting a frame to a patient |
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Definition
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Term
if the frame is crooked with the right side higher then the left which is not a possible cause |
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Definition
the pantoscopic tilt of the right side needs to be increased |
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Term
the main for the use of lenticular lenses for high powers would be |
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Definition
they are lighter in weight |
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Term
a patient come back to the optician complaining of pain behind the ears possible causes are |
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Definition
temple tension too great
uneven pressure
temple end pieces angled in too much
ALL OF TH E ABOVE |
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Term
what type of frame may be heated until it bends under its own weight |
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Definition
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Term
the step fro finishing a lens (in correct are ) |
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Definition
calculation spotting centeration blocking edging |
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Term
why is it necessary to take the B measurement |
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Definition
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Term
for every 2 degrees of pantoscopic tilt the optical center should be |
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Definition
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Term
usual reading level is considered to be ? below |
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Definition
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Term
a bifocal wearer having difficulty accommodating could most ofter be helped by adding ? to his prescription |
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Definition
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Term
which of the following is essential to place a prescription |
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Definition
lens prescription
frame name size and color
customers fitting dimensions
ALL OF THE ABOVE |
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Term
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Definition
makes people feel like they are walking downhill |
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Term
which statement is correct |
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Definition
polycarbonate lenses block UV radiation |
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Term
a number 3 tint is absords |
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Definition
80%of the light entering the lens |
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Term
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Definition
increase transmission
reduce reflection
increase vision |
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Term
a patient complains that his old glasses have better visual acuity than the new glasses (same RX)what should an optician do ? |
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Definition
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Term
a patient complains of too much pantoscopic tilt .what should the optician do |
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Definition
angel the temples upward from the endpieces |
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Term
a patient with a perscription should wear a small frame to minimize |
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Definition
decentration
thinkeness
weight
ALL OF THE ABOVE |
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Term
what shape frame should be worn by high minus power |
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Definition
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Term
active people should wear what type of temple |
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Definition
comfort cable or riding bow |
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Term
people that have glasses on and off should wear ? types temples |
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Definition
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Term
within the first few minutes of contact with a new patients |
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Definition
generate in the patient confidence in your ability |
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Term
what can you expect medicare to cover |
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Definition
corrective lenses following cataract surgery |
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Term
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Definition
1m
and 1m is
100cm
1000mm
40in |
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Term
prism tolerance in the vertical meridian is |
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Definition
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Term
as a general rule patient tolerance for prism imbalance in horizontal meridian is |
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Definition
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Term
the cylinder axis tolerance for a 0.25D cylinder is |
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Definition
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Term
the cylinder axis tolerance for a 0.75D cylinder is |
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Definition
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Term
the cylinder axis tolerance for a 1.00D cylinder |
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Definition
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Term
the cylinder axis tolerance for a 2.00D cylinder is |
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Definition
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Term
the tolerance for lens thickness when specified for special prescription purposes is |
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Definition
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Term
the segment location tolerance in vertical (segment height )meridian in a mounted |
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Definition
pairs should match within 1.0mm of specification |
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Term
lens calipers are used to measure lenses for |
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Definition
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Term
the prism measurement indicator found in a lensometer is called |
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Definition
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Term
the instrument that can help you determine a heat temperd glasslens or stress in the lens is |
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Definition
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Term
line axis pliers are used fro purpose of |
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Definition
strightening lens axis in zyl frames |
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Term
glass lenses for stander use must with stand |
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Definition
5/8inc steel ball dropped from a height of 50inc |
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Term
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Definition
zylonite/zyl orignally the most used material for plastic frames
cellulose propionte can be made thinner and lighter then zly
nylon lightweight hypollergenic and relatively unbreakable (good for sport wear gl)
rubber sometimes used for sport eyewear and sungl
carbon fiber adding carbon power gives plastic frame the streng5h of mental frame while keeping them lightwight
polyamide/copolymideblend of nylon that features durability reduced weight and flexbility considered hypo allergenic (never place in salt pan ,shinkage occurs when heated,dont clean with isoproply alcohol or products containing alcohol)
opty opty is considered thermoelastic has memory
kevlar also used for bullet prof vests and sports equlpments because of high tensile strength
polycarbonate reduced weight and fixibity hold translucent color well highly scr resistast
cellulose nitrate the first plastic uses it is flammable and unstable it is no longer used |
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Term
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Definition
zylonite /zyl orginally the most used material for plastic frame
cellulose propionate can be made thinner and lighter then zly
nylon lightweight hypoallergenic and relatively unbreakable (especially effective for sports and safety frame )
robber sometime used sports eye wear and sunglasses
carbon fiber adding carbon power gives plastic frame the straight of mental frame while keeping them light wight
polyamide/copolyamide blend of nylon that features durabilty reduced weight .flexibility considered hypo-allergenic ,never place poly amide frame in salt pans shrinkage occurs when heated ,don't clean with isopropy alcohol or products containing alcohol
opty opty is considered thermoplastic has memory
kevlar also used for bullet proof vest and sports equlpment because high tensite strength
ploycarbonte reduced weight and flexibility holds translucent color well and highly scratch resistant
cellulose nitrate the first plastic used it is flammable and unstable (no longer used )
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