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ABO
| Term | Definition |
|---|---|
| the eye is made up three layers. | Fibrous tunic, sclera, cornea. Middle layer-vascular tunic iris,choroid and ciliary body. inner layer-nervus tunic retina |
| The cornea consist of 5 layers which in order from anterior to posterior are. | Epithelium,descemets membrane,stroma,bowmans membrane,endothelium |
| The amount of ligth entering the eye is controlled by the: | Iris |
| about how many million RODS and CONES are located in the periphery of the Retina? | 120 million RODS 6 million CONES |
| The 6 extraocular muscles responsible for stabilization of the eye are: | Lateral rectus Medial rectus Superior rectus Inferior rectus Superior oblique Inferior oblique are responsible for stabilization. |
| When the eye has a tendency to turn from it's normal position it is called: | Phoria |
| When the eye has a definite or obvious turning from it's normal position it is called: | Tropia |
| Phorias and tropias are further defined by their direction such as: | Eso exo hypo hyper |
| Fusion occurs in the | Brain |
| Aqueous humor is produced by the | Ciliary Body |
| The index of refraction of the cornea is | 1.37 |
| Focal length | f=1/D -para negativos + para positivos |
| Given an Rx of: Plano +1.00 x 090 when ground the resulting lens is prescribed for which of the following conditions? +1.00-1.00x180 | Simple hyperopic astigmatism |
| The wavelength of 700nm is seen as what color: | Red |
| In a minus powered lens light rays. and come to a focal point. the lens. | Diverge in front of |
| Light rays pass through a lens and converge at a point 50cm behind the lens what is the power? | 2.00 D |
| 1 Prism Diopter can be described as deviating a ray of light: | 1 meter / 1 centimeter |
| 3 Prism Diopters base in on the right eye can also be described as | 3 @ 000 degree |
| Using Prentice's Rule a -4.00 lens must be decentered.to induce 1.00 Prism Diopter: | 2.5 4x2.5=10/10=1 ^= Pxdec,mm/10 |
| The index of refraction is lowest in | Air |
| When the direction of light changes as it passes from one medium to another it is called | Refraction |
| The focal length of a +2 diopter lens is | +50cm f= 1/D metros o cm |
| A +3.00D lens has the following prismatic effect 8 mm below the optical center: | 2.4 base up. 3x8/10=2.4 Positivos against Pris= poder distancia en cm. |
| One prism diopter: | Deviates a ray of light 1 cm at a distance of one meter |
| The P.D. written on the order is mistakenly noted as 70 mm when the actual measurement should be 66 mm. What unwanted prism would be found in the prescription if the distance prescription is O.U. -15.00D sphere? | 3.D base in each eye 70-66=4/2=2*15=30/10=3. Negativos cortos base in. |
| 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. PD | Near |
| 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? | Increase minus power effect. |
| ANSI | The American National Standards Institute is a private agency who purpose is to set commercial and industrial standards. |
| The ANSI document covering ophthalmic standards | Z80.1 |
| Which of the following categories of lenses are NOT exempt from drop ball testing? | These lenses are exempeted from testing: Prism segment multifocal slab-off prism lenticular cataract iseikonic depressed segment one-piece multifocal bioconcave myodisc minus lenticular custom laminate and cemented assembly. |
| According to ANSI standards a lens with 0.50 D of cylinder must have an axis within | 7 degrees |
| Which agency govenrs Eyeglasses and Contact Lenses? | The Food and Drug Administration enforces laws related to the production and labeling of food drugs and cosmetics. Contact lenses and eyeglasses are considered medical devices and fall under the jurisdiction of the FDA. |
| The governmental agency established for the purpose of reducing deaths injury and illness in the workplace is | OSHA The Occupational Safety and Health Administration is a federal government agency established for the purpose of reducing deaths injury and illnesses in the workplace. |
| The ASTM institute sets standards for which of the following ophthalmic products: | Sports Eyewear. The American Society for Testing Materials sets standards for sports-related products. |
| In drop ball testing a. ball is dropped from. on to the front surface of a lens. | a 5/8 ball is dropped from 50 in on to the front surface of a lens. |
| In 1987 the OLA Optical Laboratories Association reminded offices about their duty to warn patient: | About the impact resistance of various lens materials. |
| LENS DESIGN QUIZ The vertical difference in power between lenses in the following Rx s:O.D.-1.00 +0.50 x 045 O.S. -1.00 +0.50 x 090 | Od -. 50-.50*135 Os -. 50-.50*180 . 25sph. Por cada 45 grados se gana o pierde. 25 dioptrias. |
| A lens of -2.00 +2.00 x 90 power corrects | 0-2.00x180 Simple myopic astigmatism |
| Equiconvex flat convex and meniscus are ALL types of: | Plus lenses |
| Using the prescription +2.00 -1.50 X 45 what is the power of the lens at the 90th meridian? | 2.00-.75=125 Mitad del cyl cada 45grados |
| How much cylinder power is in effect at the specified axis? | 0 poder en el eje marcado |
| Equiconcave flat concave and meniscus are ALL types of | Minus lenses |
| How much cylinder power is in effect 90 degrees away from the specified axis? | 100% |
| A plus lens: | Converges ligth |
| Using the prescription -1.00 -1.50 X 90 what is the power of the lens at the 180th meridian? | -2.50 X180 |
| The spherical equivalent of the lens +1.00 +2.50 x 90 is: | +2.25D +3.50-2.50 -2.50/2= 1.25 +3.50-1.25= 2.25 |
| Which of the following lenses has no power in the 90 meridian? | +1.00-2.00x45 45 hacia el 90 mitad 1-1=0 |
| A lens having one concave and one convex surface is called a: | Meniscus lens |
| The relationship of front and back curvatures on a spectacle lens will determine: | Refractive power |
| AR coatings cause light incident upon the lens to be | Transmitted |
| What lens treatment best reduces glare from water and road surfaces? | Polarized |
| Cataract surgery removes the crystalline lens of the eye causing the patient to lose the ability to focus. This condition is known as | Aphakic |
| The refractive index of CR-39 is: | 1.498 |
| It is generally accepted procedure to fit the top of the trifocal segment to the: | Bottom edge of the pupil |
| What are CONES | Day vision receptors |
| Macula | Is positioned in the Retina. |
| What is the average eye size? | 1/8 inches long |
| What are Rods. | Peripheral vision receptors |
| A prism | A prism only deviates/shifts lights, not focuses it. |
| Another term for Eyelids | Palpebrae |
| 7. Who is the person that gives training for ocular muscle imbalances? | Orthoptist |
| 8. What is situated on the visual axis near the posterior surface of the lens in a normal eye? | Nodal point |
| 9. What is positioned on the point where the optic nerve leaves the globe? | Blind spot |
| 10. What is thejuncture of the upper and lower eye lids? | Medial y lateral canthus |
| Hyperopia | Farsightedness |
| Myopia | Nearsightedness |
| 7. What is at hejunction of the cornea and the sclera? | Limbus |
| 7. What is at hejunction of the cornea and the sclera? | Limbus |
| 8. What is the average pupil size under normal lighting conditions? | 3-5mm |
| What is Oscillopsia? | Sensation of oscillation of the visual field |
| What is Glaucoma? | Intraocular pressure exceeds normal limits |
| What is Nystagmus? | Involuntary rapid movement of the eye |
| What is Aniseikonia? | Unequal size of retinal images |
| What is Color blindness? | No cone vision |
| 9. What are Lenticular lenses used for? | Apakia |
| What is Amblyopia? | Loss of vision through disuse Desuso |
| Contraction of the pupil. | Miosis |
| 3. When parallel rays of light enter a prism, the light is deviated: | Towards the base |
| 8. Instrument used to examine the anterior parts of the eye under high magnification. | Slit-lamp |
| Dilation of the pupil. | Mydriasis |
| One meter is equal to | 39.37 inches |
| 3. The theory describes light as traveling through space in minute bursts of energy. | Corpuscular |
| 4. The index of refraction of any given transparent material can be determined by: | dividing the speed of light in air by the speed of light in the material |
| 5. The focal length of a +1.00 diopter lens is: | 100cm |
| 7. Visible light is part of the overall spectrum of radiant energy. Although the range of wavelengths of which are perceived as visible light can vary with the individual. It is generally understood to lie between: | ©390 and 750 nanometers |
| 9. Light travels through a certair transparent medium at the rate of approximately 109.412 miles per second the index of refraction of that medium is: | 1.70 N=c/v 186000 Miles or 300000 km per sec. 186000 /109.412= 1.70 |
| Effective lens power | |
| 1. Decentering a plus lens upward will result in: | Base up |
| 2. Rays emanating from one point source of light are said to be: | Diverging |
| 3. The distance between the crests of two waves is called the: | Wavelength |
| 5. How many millimeters are in an inch? | 25.4 |
| 7. T/F: A diverging lens produces a virtual image. | True |
| 10. A pair of +4.00 lenses was ordered from the lab with a PD of 59. When these lenses were ver- ified, it was determined that the optical centers were positioned 4 mm too wide. How much prism was induced in each eye and which direction is the bas | . 8 prism base out |
| 1. Myope proper frame points | 1. Keep frame size small 2. plastic frames will help guide edge thickness 3. choose frames with rounded corners |
Created by:
Aldojeda444