ABO, ABO Study Guide – Flashcards
Unlock all answers in this set
Unlock answersquestion
Prentice Rule
answer
(Power x distance in mm) /10
question
Cornea index of refraction
answer
1.37
question
Tear Film, Vitreous index of refraction
answer
1.33
question
Crystalline lens index of refraction
answer
1.42
question
Optical Standard index of refraction
answer
1.53
question
Crown Glass index of refraction
answer
1.523
question
High index of refraction
answer
1.74
question
CR-39 index of refraction
answer
1.49/1.50
question
Poly index of refraction
answer
1.586
question
Air
answer
1.00
question
How fast does light travel through air
answer
186,000 mi/sec
question
MBS formula
answer
ED+2 (decentration)+2
question
Focal length formula
answer
1/Dioptic Power power
question
Dioptic Power formula
answer
1/Focal Length
question
Antimetropia
answer
Rx with unlike signs in both eyes
question
Anisometropia
answer
Difference of 2 diopters btwn OD & OS
question
Anisiekonia
answer
When images from right and left eye are so different the brain can not achieve fusion
question
What is the Radius of a 1 diopter curve?
answer
530mm
question
Radius formula
answer
530/Power = Radius
question
Power formula
answer
530/Radius = Power
question
Vertical Decentration formula
answer
Seg.ht. - B/2
question
How much HORIZONTAL prism tolerance is allowed?
answer
2/3 of a diopter -or- 0.667
question
How much VERTICAL prism tolerance is allowed?
answer
1/3 of a diopter -or- 0.333
question
Base Curve tolerance
answer
+/-0.75
question
Sphere Tolerance up to 6.50
answer
+/- 0.13
question
Sphere Tolerance above 6.50
answer
+/- 2%
question
Cylinder Tolerance >1.50
answer
+/-2°
question
Cylinder Tolerance >0.50 / less than or equal to 1.50
answer
+/-3°
question
Cylinder Tolerance >0.25 / less than or equal to 0.50
answer
+/-7°
question
Cylinder Tolerance >0.00 / less than or equal to 0.25
answer
+/-14°
question
Drop ball test for Safety lenses
answer
5/8ths in diameter, weighing 0.56oz dropped 50ft
question
Frame PD
answer
A box + DBL
question
Total decentration
answer
Frame PD - Patient PD
question
Base IN (MINUS)
answer
If frame PD is GREATER than customer PD
question
Base OUT (MINUS)
answer
If frame PD is LESS than customer PD
question
Which layer of the cornea is highly regenerative?
answer
Epithelium
question
Which area of the retina is capable of perceiving the greatest amount of detail?
answer
Fovea centralis
question
Tonometer
answer
Used for intraocular pressure
question
What is another name for Lensometer?
answer
Focimeter
question
Thickest layer of the cornea
answer
Stroma
question
What is the main focusing structure of the eye
answer
Ciliary process
question
Emetropic
answer
Perfect Vision
question
Ametropic
answer
Needs correction
question
Thindex glass
answer
1.8
question
High light glass
answer
1.74
question
Flint glass
answer
1.69
question
3 eye layers/tunics
answer
Layer #1- Protective Layer #2- Nourishing Later #3- Light Sensitive
question
Cellulose Acetate (Zyle)
answer
Non-flammable, durable, avail in diff colors
question
Layer #1
answer
Sclera, Cornea, Anterior Chamber
question
Layer 2
answer
Choroid, Ciliary Body, Iris, Crystalline Lens
question
Layer 3
answer
Retina, Rods & Cones
question
Red
answer
651-750
question
Blue
answer
466- 500
question
Green
answer
501- 560
question
Violet
answer
400- 465
question
Orange
answer
591-650
question
Yellow
answer
561-590
question
UVA
answer
330-400
question
UVB
answer
275-300
question
UVC
answer
200-275
question
Air
answer
1.00
question
Water
answer
1.33
question
Geneva Lens/ Lab Tools
answer
1.53
question
Crown Glass
answer
1.523
question
CR-39
answer
1.49
question
Poly
answer
1.586
question
Hi Index
answer
1.67
question
Optyl
answer
Epoxy material, cannot be burned or overheated
question
Cellulose Proprionate
answer
Molded rather than cut
question
Gold
answer
Soft material, high cost, won't keep adjustment
question
Silver
answer
Too soft to use in manufacturing
question
Stainless steel
answer
Non-corrosive, strong, light weight
question
Aluminum
answer
Light weight, long lasting, can be anodized for diff color
question
Titanium
answer
Very light weight, durable, avail in diff colors and styles
question
Nylon
answer
Synthetic material. Made if coal, water and air. Used in children's frames.
question
Dress Drop Ball
answer
5/8 inch diameter .56 oz
question
Safety Drop Ball
answer
1 in diameter 1.5 oz weight
question
Ht of drop ball drop
answer
50 inches
question
Total weight of drop ball apparatus
answer
27 lbs
question
ANSI
answer
Started 1915. American National Standards Institute
question
OSHA
answer
Occupational Safety and Health Administration
question
FDA
answer
Food and Drug Administration
question
FTC
answer
Federal Trade Commission
question
Eyeglass I
answer
Prescription Release Rule
question
Eyeglass II
answer
Scope and form of practice restrictions
question
Cornea Index
answer
1.37
question
Anterior/Aqueous Chamber
answer
1.33
question
Crystalline Lens
answer
1.42
question
Amblyopia
answer
Lazy eye
question
Strabismus
answer
One lazy eye
question
Ametropia
answer
Any conditions which results in refraction error
question
1 inch
answer
2.54 cm
question
Anesekonia
answer
Dissimilar image sizes
question
Anisocoria
answer
Uneven pupil size
question
Anisometropia
answer
Unequal/diff powers/image size
question
Antimetropia
answer
Opposite signs in power
question
Aphakic
answer
Removed crystalline Lens benefits from progressive
question
Pseudophakic
answer
Implanted crystalline lens
question
Asthenopia
answer
Eye fatigue due to tired eye muscles
question
Blepharitis
answer
Inflammation of eye lid margin
question
Chromatic aberration
answer
White light broken into component part
question
Corneal ulcers
answer
Bacterial infection
question
Depth perception
answer
Objects with relief in their positioning
question
Diplopia
answer
Double vision
question
Distortion
answer
Plus- pin cushion minus- barrell
question
Emmetropia
answer
Normal eye
question
Entropian
answer
Lashes turned inward toward eye
question
Esophoria
answer
Eye turns inwards
question
Exophoria
answer
Eye turns outwards
question
Glaucoma
answer
Pressure in eye
question
Hordeolum
answer
Inflammation/pus in eye lid margins
question
Keratoconus
answer
Cone shaped cornea
question
Nystagmus
answer
Photophobia
question
Nystagmus
answer
Corrected with fresnel prism
question
Phoria
answer
Tendency of eye to move
question
Pinguecula
answer
Yellow thickened tissue
question
Ptosis
answer
Droop of upper eyelid
question
Pterygium
answer
Triangular shaped thickening of conjuctiva; scars cornea
question
Scotoma
answer
Blind spot in visual field
question
Sub-conjunctival hemmorage
answer
Blood in conjunctiva tissue
question
Suppression
answer
Brain ignores image
question
Tropia
answer
Abnormal turning of eye
question
Snellen chart
answer
20/20 8.87 cm tall
question
MBS
answer
2X Dec+ ED
question
Slab off
answer
Most minus/ least plus
question
Prism
answer
Plus wide- out Plus narrow- in Plus high- up Plus low- down Minus wide- in Minus narrow- out Minus high- down Minus low- up
question
Orthoptist
answer
Person who gives training for ocular muscle imbalances
question
Opthalmoscope
answer
Illuminates and inspects the interior of the eye
question
Keratometer
answer
Measures curvature of the cornea
question
Tonometer
answer
Measures intraocular pressure
question
Optic chiasm
answer
Where the optic nerves from each eye cross and are recombined
question
Occipital lobe
answer
Portion of the brain where Vision occurs
question
Extraocular muscles
answer
Assists in eye movement
question
Canthus
answer
Juncture of the upper and lower eye lids
question
Average eye size
answer
1 1/8 inches long
question
Blind spot
answer
Positioned on the point where the optic nerve leaves the globe
question
Cones
answer
Color receptors of the retinal, Normal illumination/day Vision receptors, Photophobic receptors
question
Rods
answer
Receptors for peripheral, scotopic and black and white Vision
question
Macula
answer
Positioned on the retina
question
Crystalline lens
answer
Filters UV rays, just behind the pupil, focuses light on the retina
question
Nodal point
answer
In a normal eye, this is situated on the visual axis near the posterior surface of the lens
question
Extrinsic muscles
answer
Have tendons inserted into the sclera and tenons capsule
question
Optic axis
answer
Passes thru the posterior pole of the globe and the anterior pole of the cornea
question
3-5 mm
answer
Average pupil size under normal lighting conditions
question
Limbus
answer
Junction of the cornea and the sclera
question
Aqueous Humor
answer
Constantly being replaced, produced by the cicialry processes
question
Esophoria
answer
Tendency of the visual axis to deviate inward when resting
question
Exophoria
answer
Tendency of the visual axis to deviate outward when resting
question
Ametropia
answer
Any refractive error
question
Oscillopsia
answer
Sensation of oscillation of the visual field
question
Conjunctivitis
answer
Commonly known as pink eye, pinkish discoloration of the inner surface of the lids and outer surface of the sclera
question
Strabismus
answer
Disorder in which the eyes don't look in exactly the same direction at the same time
question
Myopia
answer
Nearsightedness
question
Hyperopia
answer
Farsightedness, Infants are usually born this way
question
Astigmatism
answer
Due to unequal curvaturers of the cornea
question
Presbyopia
answer
Loss of the ability to focus on near objects with age
question
Aniseikonia
answer
Unequal size of retinal images
question
Glaucoma
answer
Disease characterized by an intraocular pressure which exceeds normal limits
question
Keratoconus
answer
A cone shaped deformity of the cornea
question
Amblyopia
answer
Loss of vision thru disuse, treated with occluder lens (patch opposite eye)
question
Color blindness
answer
No cone vision
question
Diplopia
answer
Seeing one object as two, seeing double
question
Convergence
answer
Process of directing the visual axis of the eyes to a near point
question
Accommodation
answer
Focusing on near objects by the crystalline lens, peaks at age 10 and decreases throughout life
question
Scotoma
answer
Area of the retinal Vision loss, blind spot on the eye
question
Aphakic
answer
Eye from which crystalline lens has been removed, usually after cataract surgery
question
Photophobia
answer
Abnormal sensitivity to light
question
Nystagmus
answer
Involuntary rapid movement of the eye, often associated with photophobia
question
Divergence
answer
Ability to maintain singular binocular vision with both eyes
question
Adduction
answer
Nasal inward turning off the eyeball
question
Lenticular
answer
Corrects for apakia
question
Plus lens
answer
Corrects for hyperopia
question
Occuluder lens
answer
Used to treat amblyopia
question
Yellow/Green
answer
Portion of the light spectrum the eye is most sensitive to
question
186,000
answer
Speed of light in miles per second
question
Iris
answer
Controls the amount of light allowed through the pupil
question
Epithelium
answer
The outer most layer of the cornea, rests on the Bowman's membrane
question
Bowman's Membrane
answer
Second layer of the cornea, acts as a protective barrier
question
Stroma
answer
Between the Bowman's membrane and the Descemet's membrane, makes up 90% off the cornea thickness
question
Descemet's Membrane
answer
Separates the stoma and the endothelium
question
Endothelium
answer
The inner most layer of the cornea, removes water from the cornea, helping to keep the cornea clear
question
Dilated muscle
answer
Opens the iris to allow more light in
question
Sphincter muscle
answer
Closes the iris
question
Iris
answer
Has the ability to change the pupil size from 2mm to 8mm
question
Ciliary body
answer
Helps to achieve accommodation, surrounds the crystalline lens
question
Zonules
answer
Fibrous stands that attach to the ciliary body
question
Cornea layers
answer
What is this?
question
Palpebrae
answer
Another term for Eyelids
question
Medial canthus
answer
The point where the upper and lower eyelids meet near the nose
question
Lateral canthus
answer
The point where the upper and lower eyelids meet towards the ear
question
Eyelashes
answer
Strong hairs that run along the upper and lower Palpebral margins, they filter debris from entering the eye
question
Meibomian glands
answer
Located along the inner margin of the eyelids, secrete a liquid that keeps the eyelids from sticking together
question
Fornix
answer
Located behind the eyelid or palpebra and along the sclera, where the two layers of the conjunctiva meet and join
question
Lacrimal gland
answer
Produces the bulk of the tears, located above the lateral canthus in a depression of the bone that surrounds the eye
question
Lacrimal puncta
answer
Small openings (pores) located at the medial canthus that allow the accumulated tears to drain off the eye
question
Lacrimal canals
answer
The path the tears take from the eye to the lacrimal sacrifice and then to the nasal passage
question
Lacrimal caruncle
answer
Located at the medial canthus, produces a liquid that soothes and lubricates the eye
question
Cornea
answer
The clear lens or structure that covers the iris. The first most major structure that retracts light as it enters the eye.
question
Cornea
answer
Has no blood supply, gets all is its oxygen directly from the air
question
Pupil
answer
Opening created by the iris changing size
question
Sclera
answer
The white of the eye, thick tough and fibrous layer that provides the structure of the entire eyeball
question
Limbus
answer
Where the cornea blends into the sclera
question
Iris
answer
The colored area under the cornea that opens and closes to regulate light entering the eye
question
Lateral rectus
answer
Rotates eye laterally or out towards the ear. Attaches directly to the side of the eye and runs straight back
question
Superior rectus
answer
Eye looks up. Attaches directly to the top of the eye and runs straight back
question
Inferior rectus
answer
Eye looks down. Attaches directly to bottom of eye and runs straight back
question
Inferior oblique
answer
Eye rolls, looks up and to the side. Attaches along the lateral side of the eye and runs under the eye passing over the inferior rectus and attaches medially
question
Superior oblique
answer
Eye rolls, looks down and to the side. Attaches under the superior rectus, passes through the a bony spur known as the Trochlea, and then follow the path of the superior rectus. The raised attachment point provides the muscle the ability to give the eye rotation
question
Presbyopia
answer
When the crystalline lens can no longer change shape and provide accommodation
question
Simple myopia
answer
All the rays of light entering the eye focus at the same spot, it is the wrong spot, but they all meet at the same place. The retina is further back from the cornea
question
Myopia
answer
Corrected with minus lenses
question
Myopia RX
answer
-1.00 sphere
question
Simple hyperopia
answer
All the rays of light entering the eye focus at the same spot, it is the wrong spot, but they all meet at the same place. The retina is further forward than the cornea
question
Hyperopia
answer
Corrected with plus lenses
question
Hyperopia RX
answer
+2.00 sphere
question
Simple myopic astigmatism
answer
Some of the rays of light entering the eye fall short of their intended spot on the retina, but some fall directly on the fovea where they need to be
question
Simple hyperopic astigmatism
answer
Some of the rays of light entering the eye focus on a spot beyond the retina, but some fall directly on the fovea where they need to be
question
Compound myopic astigmatism
answer
Rays of light entering the eye do not meet at the same place, they all fall short of their intended spot on the retina, but some fall closer than others
question
Compound hyperopic astigmatism
answer
Rays of light entering the eye do not meet at the same place, they all focus on a spot beyond the retina, but some come closer to the fovea than others
question
Mixed astigmatism
answer
Some rays fall ahead of the retina while others try to focus on a spot beyond the retina. They are neither nearsighted or farsighted, they have poor vision in am areas
question
Converges
answer
Light passing through a plus lens
question
Diverges
answer
Light passing through a minus lens
