Term
| light is considered to be |
|
Definition
part of eletromagnetic specteum between 400 and 700 nm
|
|
|
Term
| the behavior of light is explained by which theory of light |
|
Definition
| a combination of wave particle action |
|
|
Term
| the breaking up of white light into it's component colors by prism is called |
|
Definition
|
|
Term
| light rays emanating from an object will be |
|
Definition
|
|
Term
| light rays originating from a distant object are described as |
|
Definition
|
|
Term
| the distance from the crest of wave to crest of the next wave is called |
|
Definition
|
|
Term
|
Definition
| the ratio of the speed of light in air to the speed of light in an optical medium |
|
|
Term
| when light travels through an optical medium of higher density it |
|
Definition
| is refracted and reflected partially absorbed |
|
|
Term
| the standard refractive index for calibration is |
|
Definition
|
|
Term
| the index of refraction is the highest in |
|
Definition
|
|
Term
|
Definition
| the ratio of light entering the lens to light leaving the lens |
|
|
Term
|
Definition
is in the middle of the spectrum
(red is the top ,green middle ,blue end) |
|
|
Term
| absorption of light in a lens can be increased by |
|
Definition
|
|
Term
| anti reflection coating (aka anti glare or AR )reduces reflection and increases transmission because of it's thickness.it is |
|
Definition
|
|
Term
| ultraviolet (aka UV)radiation is |
|
Definition
| wavelengths shorter than 380nm |
|
|
Term
| light rays passing through a prism are |
|
Definition
|
|
Term
| an object viewed through a prism appears |
|
Definition
|
|
Term
|
Definition
| has the same curvature in all meridians |
|
|
Term
|
Definition
| more powerful the lens ,shorter the focal length(remember steeper ,stronger,shorter) |
|
|
Term
the fine line on the lensometer focus at +0.75and the coarse lines focuses line focuses -1.50
axis is 20 degress the rx's is |
|
Definition
first change the +0.75 to -0.75
(thn +or -with the cly)
(-0.75+-1.50=-2.25)
so rx's is +0.75 -2.25 x20
|
|
|
Term
| the prism base of a plus lens is |
|
Definition
| at the optical center (is you drwl two plus base together you will see that OC is at the base ) |
|
|
Term
|
Definition
| change shade depending on the amount of uv striking the lens and are are heavier the crown glasses |
|
|
Term
| which of the following lenses is apt to blur a young emmetropia who is viewing a distant object |
|
Definition
| +2.00D (remember emmetropia means an eye with no ref error aka good eyes ) |
|
|
Term
| which person uses accommodation to see distance clearly |
|
Definition
|
|
Term
| a compound hyperopia patient needs a |
|
Definition
| plus toric (why cause light one light ray falls on retina and the other falls behind the retina |
|
|
Term
| which indicated the most acute distance vision |
|
Definition
20/15 (remember 20/20 is normal)
(20/50 is less)
(20/15 most) |
|
|
Term
| an aphakic patient has experienced removal of |
|
Definition
| the entire crystalline lens |
|
|
Term
RX OD -4.50 +1.50X180
OS -2.25 +1.00X045
this prescription is an obvious case of |
|
Definition
anisometropia (first transp rx)
OD SPH POWER -4.50 -1.50=-3.00
OD IS NOW -3.00 CLY BECOMES -1.50 MOVE AXIS 90D
YOU HAVE OD AS -3.00 -1.50X90
OS SPH POWER -2.25 -1.00=-1.25
OS IS NOW -1.25 CLY BECOMES-1.00 MOVE AXIS 90D
YOU HAVE OS AS -1.25 --1.00X135
is is an anisometropia because
there is more the 2D between OD & OS |
|
|
Term
| index of refraction in air |
|
Definition
Air: 1.00
Aqueous Humor: 1.33
Vitreous Humor: 1.33
Cornea: 1.37
Crystalline Lens: 1.42
CR-39 Plastic: 1.49
Crown Glass: 1.52
Polycarbonate: 1.58
High Index Plastics: 1.60 to 1.74
High Index Glass: 1.60 to 1.80
|
|
|
Term
| index of refraction in CR39 |
|
Definition
|
|
Term
| index of refraction in cornea |
|
Definition
|
|
Term
| index of refraction in crown glass |
|
Definition
|
|
Term
an RX with the OD plus sine (+)& the OS minus sine (-)
is known as |
|
Definition
|
|
Term
| a tendency of the eye to deviate from its normal position is |
|
Definition
|
|
Term
| exotropia can be corrected with |
|
Definition
| base in prism (exotropia means out )so to correct out you will in |
|
|
Term
|
Definition
|
|
Term
| abnormal sensitivity to light is called |
|
Definition
|
|
Term
| the eye disease characterized by excessive interocular pressure is |
|
Definition
|
|
Term
a patient wearing a prescription RX
OU -4.00 +4.00 X175 |
|
Definition
FIRST TRANSP RX
OU PLO -4.00 X 085
ANSWR IS =simple myopic astigmatism
|
|
|
Term
the refractive anomaly indicated by the RX
+2.75 -1.25 X135 is |
|
Definition
|
|
Term
a prescription with the
RX -2.00 +3.00X45
|
|
Definition
first transp RX -2.00 +3.00 X45
(2.00-3.00=1.00)
then move axis 90 degress
NEW RX IS +1.00 -3.00 X135
ansrw is mixed astigmatism
|
|
|
Term
|
Definition
the focal length divided into a meter
equivalent to focal lenght |
|
|
Term
|
Definition
|
|
Term
| the amount of light entering the eye is controlled by the |
|
Definition
|
|
Term
| the average pupil size under normal lighting is |
|
Definition
|
|
Term
| the eye converge ? for reading |
|
Definition
|
|
Term
| directing the visual axis of the eyes to near point is |
|
Definition
|
|
Term
| amblyopia is frequently treated with |
|
Definition
occluder lenses
(pacthing up good eye)
amblyopia aka lazy eye |
|
|
Term
|
Definition
is the distance from the cornea to the ocular surface
effects the power of the lens
varies from frame to frame |
|
|
Term
| the refracted vertex distance is the |
|
Definition
| vertex distance used by the refractionist |
|
|
Term
| vertex distance compensation for spectacle is most needed for prescriptions |
|
Definition
|
|
Term
as a rule it is best to keep the vertex distance at a minimum why
|
|
Definition
| to reduce magnification /minification effects |
|
|
Term
| aphakic patients wearing cataract lenses would find which of the following fitting techniques most beneficial |
|
Definition
|
|
Term
| a patient with -15.00D lenses which are brought closer to the eyes will have what effect on effective power |
|
Definition
increase minus power effect
remember
minus lens move closer gain power, move away losses power
plus lens move closer losses power,move away gain power |
|
|
Term
| the standard bifocal has how many measurable optical centers |
|
Definition
|
|
Term
| corrected curve lenses have |
|
Definition
|
|
Term
|
Definition
|
|
Term
| the base curve ,lens thickness and vertex distance control |
|
Definition
|
|
Term
| an advantage of a round segment over the executive bifocal is |
|
Definition
|
|
Term
| a good choice for aphkic spectacles is |
|
Definition
|
|
Term
| the progressive lens has a progressive zone or corridor where |
|
Definition
| power gradually increases |
|
|
Term
a patient is wearing glasses with two prism diopters base up in each eye
the patient will experience |
|
Definition
|
|
Term
| the part of the eye that refract the are |
|
Definition
| the cornea ,aqueous humor,crystalline lens and the vitreous |
|
|
Term
| an aphakic eye is more sensitive to light because |
|
Definition
| the crystalline lens that filters the UV radiation is no longer present |
|
|
Term
| with new glasses a patient complains that every thing appears smaller ,this could be due to |
|
Definition
| lens having to much minus power |
|
|
Term
| which of the following is recommended fro shooting glasses |
|
Definition
|
|
Term
| what color do you recommend for night driving |
|
Definition
|
|
Term
| ptosis crutch is used for a patient with |
|
Definition
|
|
Term
All the questions in the quiz along with their answers are shown below. Your answers are bolded. The correct answers have a green background while the incorrect ones have a red background.
Given an Rx of: Plano +1.00 x 090, when ground, the resulting lens is prescribed for which of the following conditions?
|
|
Definition
- Simple hyperopic astigmatism
|
|
|
Term
If the pupillary distance is measured while the patient is focusing on a point 16 inches in front of his eyes, the P.D. measured is known as the _______ P.D. |
|
Definition
|
|
Term
| The optical cross is a graphic representation used to show the _________ of a lens |
|
Definition
|
|
Term
You are fitting a patient with a Titan-10 frame, 24 DBL, 44 eye size, and 5V2 inch skull temples. The distance P.D. is only 62 mm. If by some unfortunate error the lenses are NOT decentered at all, how much prism is created in each eye? Rx O.U.-2.25-1.50x45 |
|
Definition
|
|
Term
| A characteristic most single vision CR-39 lens series have in common is |
|
Definition
|
|
Term
As the pantoscopic angle is increased: |
|
Definition
- The spherical equivalent is increased
|
|
|
Term
| A lens of -2.00 +2.00 x 90 power corrects _______ |
|
Definition
- Simple myopic astigmatism
|
|
|
Term
The vertical difference in power between lenses in the following Rx is: O.D.-1.00 +0.50 x 045 O.S. -1.00 +0.50 x 090 |
|
Definition
|
|
Term
A ptosis crutch is used to give support to: |
|
Definition
|
|
Term
A patient comes in with a prescription requiring a large amount of plus power (+12.50 diopters) and with a notation Vertex Distance 12 mm. You find that when fitted with a frame, the lens will set 14 mm from his eye. What change will be necessary in the lens to be ordered? |
|
Definition
|
|
Term
If the lenses of a patient wearing -15.00 spheres are brought closer to his/her eyes, what if any effect will this have on the effective power? |
|
Definition
- Increase minus power effect
|
|
|
Term
| Most commonly, opticians use a Geneva(aka lens clock) lens measure to |
|
Definition
|
|
