ABO Exam Prep Part 2: Basic Optic Principles Questions and Answers

UV radiation - Answer- Radiation type of wavelengths shorter than 400 nm UV C - Answer- Division of UV radiation ranging from 290-200 nm & is extremely dangerous, absorbed by the ozone layer UV B - Answer- Division of UV radiation ranging from 320-290 nm & causing sunburn, corneal burn, retinal damage, & eventually cataracts; mainly absorbed by the cornea & partly the crystalline lens UV A - Answer- Division of UV radiation ranging 400-320 nm & causing suntan & cataracts; primarily absorbed by the crystalline lens 5, 1 - Answer- The FDA requires that sun lenses transmit no more than __% of UV A & no more than __% of UV B Glare control lenses - Answer- Lenses that go beyond UV wavelength for superior protection Infrared radiation - Answer- Radiation type of wavelength 750-1400 nm Dispersion - Answer- The breaking down of white light into seven component colors Green - Answer- When white light enters the eye, this color focuses upon the retina Red - Answer- When white light enters the eye, this color focuses beyond the retina Blue - Answer- When white light enters the eye, this color focuses in front of the retina 39.37 in - Answer- One meter is equivalent to this amount of inches 25.4 mm - Answer- One inch is equivalent to this amount of mm 390-750 nm - Answer- The range of visible light Wave theory - Answer- Theory that describes light as moving in waves, like the motion of waves in water Corpuscular theory - Answer- Isaac Newton's theory that describes light as being minute particles, called photons, which originate from the light's source Index of refraction - Answer- The density of any given material Refraction - Answer- The bending of light Reflection - Answer- When a beam of light bounces back from a material; directly proportional to refractive index Absorption - Answer- The amount of light that is trapped in an optical material when light passes through; directly proportional to refractive index Transmission - Answer- The amount of light that passes through a material; inversely proportional to refractive index 290 nm - Answer- Crown glass absorbs UV light below this wavelength 350 nm - Answer- CR-39 absorbs UV light below this wavelength 1.523 - Answer- Index of refraction of crown glass 1.498 - Answer- Index of refraction of CR-39 1.586 - Answer- Index of refraction of polycarbonate 1.600 - Answer- Index of refraction of high index plastic 1.805 - Answer- Index of refraction of flint glass n = speed of light in air / speed of light in material - Answer- Formula for index of refraction 1.530 - Answer- Standard index of refraction Base - Answer- Light always bends toward the ___ of the prism Image displacement - Answer- The appearance of an image to be in a position other than the position from which the light had originally emanated Prism diopter - Answer- 1 cm / 1 m D = 1/f - Answer- Lens power in terms of focal length (m) f = 1/D - Answer- Focal length (m) in terms of lens power Prentice's Rule - Answer- Prism diopters = F * dec (mm) / 10 Real image - Answer- The type of image formed by a plus lens Virtual image - Answer- The type of image formed by a minus lens Apex - Answer- An image is always displaced toward this part of the prism Prism - Answer- A wedge of optical material Induced prism - Answer- Unwanted prism that occurs when the OC of a lens is not correctly placed in front of the patient's MRP Prescribed prism - Answer- Prism that is tested by & written into a Rx by an optometrist to assist in the redirection of muscular imbalance 2/3 D, 2.5 mm - Answer- ANSI standard for horizontal variance is ___ (D) within ___ (mm) of the MRP 1/3 D, 1.0 mm - Answer- ANSI standard for vertical variance is ___ (D) and less than or equal too ___ (mm) the MRP