ABO Exam 2023/24 study guide with 100% correct answers

The extra-ocular muscles are inserted into the sclera and serve to rotate the eye in all possible directions. There are _______of these muscles. Six The fibrous tunic is comprised of the: Sclera and cornea Fusion occurs: In the brain The aqueous fluid is continually being manufactured by: The ciliary body The ability of the eye to bring objects of varying distances to focus on the retina is known as: Accommodation When accommodation is at rest, rays of light from a distant source come to focus behind the retina. This condition is known as: Hyperopia Impulses are carried from the retina to the brain along the: Optic nerve That area of the retina capable of perceiving the greatest amount of detail is: Fovea centralis The average cornea has a refractive power of approximately: 43 diopters The layer of the cornea which is highly regenerative is: The epithelium Night vision is chiefly a function of the: Rods A tendency of the visual axis to deviate inward while the eyes are in a position of rest is known as: Esophoria A "farsighted" eye is one that is: Hyperopic The term used to indicate "double vision" is: Diplopia The condition in which the ability to accommodate for near vision becomes inadequate because of loss of elasticity of the crystalline lens is called: Presbyopia When there is a loss of vision without any apparent disease of the eye it is known as: Amblyopia A refractive error in which the rays of light do not come to a single point of focus is called: Astigmatism The condition in which the crystalline lens of the eye gradually loses its transparency with consequent loss of visual acuity is known as: Cataract An ocular disease having as its primary characteristic a sustained increase in intraocular pressure. Glaucoma The space between the front of the iris and the innermost portion of the cornea (the endothelium), this space is filled with aqueous. Anterior chamber A tendency of one eye to deviate upward is: Hyperphoria The layer of the cornea which comprises ninety percent of its thickness is: The stroma A condition in which the refractive error of one eye significantly differs from that of the other and where both eyes have the same sign (i.e. both eyes are myopic or hyperopic) is known as: Anisometropia The refractive error which results in two points of focus falling behind the retina is: Compound hyperopic astigmatism The refractive condition caused by a damaged cornea so that rays of light come to many focal points on the retina is known as: Irregular astigmatism The index of refraction of the crystalline lens is: 1.42 The index of refraction of the cornea is: 1.37 Myopia means the eye A. is nearsighted B. has distance blur C. requires a (-) minus lens D. all of the above D. all of the above The Retina contains A. lab tools B. lens information C. light receptors D. understock of frames C. light receptors Hyperopic people have difficulty seeing A. distance objects B. near objects C. everything D. nothing B. near objects How many ranges of vision do bifocals provide? A. one B. Three C. Two D. Infinite C. Two The top portion of a bifocal allows wearers to see: A. objects in the distance B. a & c C. objects beyond arm's length D. objects up to 18 inches B. a & c Characteristics of a plus (+) lens include: A. thin center B. minifies objects C. converges light rays D. corrects myopia C. converges light rays Polycarbonate lens material is: A. heavy B. tintable C. most impact resistant material D. totally scratch resistant C. most impact resistant material Which of the following would be considered a lens enhancement? A. polycarbonate B. anti-reflective coating C. progressive D. thin center B. anti-reflective coating Ultraviolet protection (UV) is not important to A. children B. women C. elderly patients D. none of the above D. none of the above The following information is required on a written prescription: A. doctor's name B. doctor's signature C. date D. all of the above D. all of the above The front surface of lenses can be measured using a ____________. Lens clock (Geneva lens measurer). High plus lenses will produce _________________ distortion while high minus lenses will produce _____________ distortion. Pin cushion and barrel. The unit of measurement for a wavelength of light is called _____________. Nano-meters (nm) The speed at which light travels is ______________, while _______________ refers to the number of wave vibrations per second. Velocity, Frequency. Give the wavelength range for UVA: __________ UVB: __________ UVC: ___________. UVA: 315-380 nm UVB: 290-315 nm UVC: 210-290 nm Wavelengths in the ______________ colored part of the spectrum are thought to provide the clearest vision. Green The focal length of a .50 D lens is _________________. 2 meters. There are _________________ millimeters in one meter. One thousand The color in the visible spectrum with the shortest wavelength is _________________. Violet Wavelengths that are "in phase" produce: A. destructive interference B. high frequencies C. a big reflection D. no reflection C. a big reflection Anti-reflective coating causes an ______________ situation. out of phase (destructive interference) Minus lenses combine prisms: A. base to base B. apex to apex C. apex to base D. front to bakc B. apex to apex Characteristics of a plus lens include: A. "with motion" B. real focal point C. concave in shape D. strengthens as vertex shortens B. real focal point A prism re-directs light towards its ______________ while the object viewed will appear to be displaced towards the ________________. Base; Apex. In mixed astigmatism: A. two focal lines form in front of the retina B. one focal line forms on the retina and the other behind the retina C. one focal line forms on the retina and the other in front of the retina D. one focal line forms in front of the retina and the other forms behind the retina D. one focal line forms in front of the retina and the other forms behind the retina In compound hyperopic astigmatism: A. two focal lines form in front of the retina B. two focal lines form behind of the retina C. one focal line forms on the retina and the other in front of the retina D. one focal line forms in front of the retina and the other forms behind the retina B. two focal lines form behind of the retina In simple hyperopic astigmatism: A. two focal lines form in front of the retina B. one focal line forms on the retina and the other behind the retina C. one focal line forms on the retina and the other in front of the retina D. one focal line forms in front of the retina and the other forms behind the retina B. one focal line forms on the retina and the other behind the retina