Anatomy and Physiology of the Human Eye

Question The extra occular muscles are inserted into the sclera and serve to rotate the eye in all possilble directions. There are_______of these muscles in each eye. The fibrous tunic is comprised of the: Fusion accours in the? The aqueous fluid is continually being manufactured by The ability of the eye to bring objects of varying distance to focus on the retina is knows as: When accommodation is at rest, rays of light from a distant source come to focus in front of the the retina. This condition is known as: When accommodation is at rest, rays of light from a distant source come to focus behind the retina. This condition is known as: Impulses are carried from the retina to the brain along the: While reading, or performing other near vision task: Th area of the retina capable of perceiving the greatest amount of detail is The average cornea has refractive power of approximately The layer of the cornea which is higly regenerative is: Night vision is chiefly a function of the: A tendency of the visual axis to deviate inward while the eyes are in position of rest is known as: A "farsighted" eye is one that is: The term used to indicate "double vision" is: The condition in which the ability to accommodate for near vision becomes inadequate because of loss of elasticity of the crystalline lens is called: When there is a loss of vision without any apparent disease of the eye it is known as: A refractive error in which the rays of light do not come to a single point of focus is called: The condition in which the crystalline lens of the eye gradually loses its transparency with consequent loss of visual acuity is known as: An ocular "disease " having as its primary characteristic a sustained increase in intraocular pressure The space between the cornea and iris that is filled with aqueous A tendency of one eye to deviate upward is: The photosensitive receptors of the retina which are responsible for sharp visual acuity and color perception are the: The layer of the cornea which comprises 90% of its thickness is: A condition in which the refractive error pf one eye significantly differs from that of the other and where both eyes have the same sign (both eyes are myopic or hyperopic) is known as: The refractive error which result in two points of focus falling the retina is: The refractive condition caused by a damage cornea so that rays of light come to many focal points on the retina is known as: The transparent, colorless mass of soft, gelatinous material which fills the eyeball behind the lens is the: The index of refraction of the crystalline lens is: The cornea has an index of refraction of: When the optical centers of a pair of plus lenses are positioned narrower than the PD, it produces prism base_____. When the optical centers of a pair of minus lenses are positioned narrower than the PD, it produces prism base____. Answer Six.. Sclera, Cornea Brain The ciliary body Accommodation Myopia Hyperopia Optic nerve The pupil constrict The eye converge The crystalline lens accommodates Fovea centralis 43 diopters The epithelium Rods Esophoria Hyperopic Diplopia Presbyopia Amblyopia Astigmatism Cataract Glaucoma Anterior chamber Hyperphoria Cones The stroma Anisometropia Compound hyperopic astigmatism Irregular astigmatism Vitreous humor 1.42 1.37 In Out When patient looks through a plus lens above the optical center, it produces prism base_____. When patient looks through the minis lens below the optical center, it produces prism base_______. How much prism is induced 5mm away feom the optical center of a +2.00 diopter lens? How much prism is induced 10mm away from the optical center of a -0.25 diopter lens? How much prism induced 2mm away from the optical center of a +16.00 diopter lens? In verifying a pair of spectacles which have recently beeen returned from the lab, you notice that the optical centers are positioned 61mm apart. The work order indicates the patient's PD measures 64mm and the prescription calls for -3.00 sphere in each e A patient prescription calls for OD:+4.75 OS: +2.50. The optical centers of the finished spectacles are found to be positioned 4mm too wide. How much total prism is induced and in which direction is the base? Light directly on retina. Normal eye condition Front of retina Back of retina One concave, One convex Use to measure the base curve. Measure accular surface. Advance presbyope Use to detect internal lens stress. Use to measure vertex distance. Use to measure lens thickness. Investor of executive bifocals? Absence or gone of crystalline lens due to cataract. Natural cryst lens Inflimmation of retina Both eyes have definite turning inward. Tendency Deffinite turning Fitting the child for bifocals Most be useful for electrician looking up the light Clearest, clear of vision, opposite blind spot Good vison, sharp, cons & rods Curving the temples around the head To minimize the aberrations Pow Different size of retina Corrected by lens having cylinder power Diopter power generated by eye optical sytem Most color of visible spectrum contributes to blurry vision Common trifocals power Direction of light directed when it passes through a prism. Produces virtual image Created barrel distortion Base curve for minus lens range fall? Base curve for plus power lenses range fall? The point through which light rays pass without being refracted? Thin in rhe center. Effective power becomes stronger as lens move closer Speed of light in crown glass? Range of wavelength Down Down 1.0 🔼 Formula: 🔼 = f x dec(mm)/10 .25🔼 (10)x (0.25)/10=2.50/10=0.25🔼 3.2🔼 (16)x(2)=32/10=🔼3.2 0.9 base out 64-61=3 (-3.00)x(3)=9/10=0.9 bo .95🔼BO (4.75)x(2)=9.5/10=0.95 .5🔼BO (2.50)x(2)=5/10=0.5 =1.45🔼BO total =1.45 Emmetropia Myopia Hyperophia Meniscus Lensclock Trifocals Polariscope Distometer Lens caliper Benjamin Franklin Aphakia Phakia Retinitis Convergent strabismus Esophoria Exophoria Bisecting the center of the pupil Double D Fovea Macula Bowing "Best Form" Power of wear, position of wear Aniseikonia Astigmatism 60 Blue 50% off Add Toward a good the base Diverging (-) High minus lens Plano to +4.00 D +6.00 to -10.00D Optical center Minus lens. 122,000 miles/second 380.....740 nm Material characteristic that describe density. Straight top, Flat top Lens curvatures Drooping lid (Ptosis crutch) give support to the upper eyelid The index of refraction is lowest in: When parallel rays of light enter the prism, the light is deviated: One meter is equal to ______inches. Two meters is equal to__________centimeters. The index of refraction of any given transparent material can be determined by: The speed of lights in air is approximately: When the direction of light is deviated in the course of passing from one transparent medium to another it is known as: Light travels through a certain transparent medium at the rate of approximately 109,412 miles per second. The index of refraction of that medium is The _____theory describes light as travelling through space in minute bursts of energy. If converging lens has a focal length of +2.00 meters, its power is: Visible light is part of the overall spectrum of radiant energy. Although the range of wavelengths of which are perceived visible light can vary with the individual, it is generally understood to lie between: If a prism can displace an image one centimeter at a distance of one meter,it said to have a power of: The distance between the crests of two waves is called the: The focal length of a -5.00 diopter lens is: Decentering a plus lens upward will result in: Prentice's Rule states that the amount of induced prism is equal to: A diverging lens produces a______image. Rays emanating from a point source of light are said to be: A pair of +4.00 spectacle lenses were ordered from the laboratory with a PD of 59mm. When this lenses are verified, it was determined that the optical centers were positioned 4mm to wide. How much prism was induced in each eye and in which direction is th A pair of spectacles were ordered w/ a prescription of -2.00D in each eye and PD of 63mm. They were received from the laboratory with the optical centers set 66mm apart.How mich total prism was induced & in which direction is the base? What part of electro magnetic spectrum contains uv energy? Which color absorbs light?(white reflects light)! What will prism do? For patient requiring no prescribe prism, where is the mrp? 1.The index of refraction of the material, 2. the thickeness of the lens, and the 3. relationship between the front and the back of lens. These ate three thing that What happen when lights hits lens? Wha is the vertical power of this lens -7.00 -1.00@45 This lens are made of a hard resin material: Bifocals are used to correct for a condition called: Astigmatism is corrected by lens having: The thinnest point of an individual safety lens should not be less than: Due to a change in the curvature of the anterior surface of the crystalline lens: A reverse slab-off should be used in the lens which has the: What is the index of refraction of the crystalline lens:1.427 A lens whose power is half a diopter has focal length of: Specific gravity Fused bifocal Geneva lens Ptosis crutch Air Towards the base 39.37 200 Dividing the speed of light in air by the speed of light in the material. 186,000 miles per second Refraction Deviate/refract 1.70 N=186,000/109,412 miles per second =1.69 =1.70 Corpuscular +0.50 diopters P=1/F 1/+2.00 +0.50 390 and 750 nm 1 prism diopter Wavelength -20 cm F=1/P =1/-5.00 =0.2m convert to cm =-20 cm Base up prism Power of lens times the decentration in meter /10 P x dec /10 Virtual Diverging 0.8 prism diopter base in 🔼=Pxdec/10 +4.00x4=16/10 =1.6/2 0.8 0.6 prism diopters base in 66-63=3mm 🔼=Pxdec/10 =-2.00x3mm=6/10 =0.6 200-400nm Black Displace rhe image of the apex The optical center (OC) Affect the power of a lens Absorption, transmission, reflection +6.50 Zyl Presbyopia Cylinder power 2.0mm Accommodation Most plus 2000mm A progressive lens is considered: Three Chambers of the eye Temporal rectus Superior oblique Nasal rectus Inferior oblique Superior rectus Inferior rectus Outer protective coat of the eye. Consist of Sclera & cornea Also known as uvual tract. Consist of Iris, Ciliary body, Choroid: Consist of the retina: A one piece bifocal Anterior chamber Posterior chamber Vitreous humor 6 muscle in each eye Fibrous tunic (external) Vascular tunic (middle) Neural tunic (internal)