Term
| What is the range of the visible spectrum? |
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Definition
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Term
| What is the range of ultraviolet radation for UVA, UVB, and UVC? |
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Definition
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Term
| What is the range of infrared (IRa, IRb, IRc)? |
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Definition
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Term
| What is a comfortable level of illumination? |
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Definition
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Term
What do you call one or more areas in the field of vision of sufficient brightness to cause
1) an unpleasant sensation
2) a temporary blurring of vision
3) a feeling of ocular fatigue |
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Definition
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Term
| What do you call the type of glare when a person exposed to a variety of reflected light sources such as at the beach has a difficult time differentiating objects of similar contrast? |
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Definition
Veiling or disability glare
e.g. on the beach, with reflections from water, sand, etc. |
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Term
| What type of glare is when a person adapted to low level illumination experiences discomfort when exposed to high level illumination rapidly? |
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Definition
| 1) discomfort glare, e.g. being hit with high beams while driving at night |
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Term
| How big must the difference in illumination be in order to experience discomfort glare? |
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Definition
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Term
| What do you call stray light that reduces visual comfort but does not interfere with reolution? |
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Definition
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Term
| What do you call the type of glare produced when light reflects off the snow and ice? |
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Definition
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Term
| What type of glare would you call a cases where dazzingly bright headlights on a road make it nearly impossible to see someone in dark clothing walking along the side of the road? |
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Definition
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Term
| What type of glare would call someone working at a computer screen in front of a bright window? |
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Definition
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Term
| What wavelength of light does the crystalline lens absorb that causes it to fluoresce and give off a wavelength of 530 nm? |
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Definition
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Term
| What color will a contact lens practitioner see the patients pupil giving off when viewing the eye with a UV lamp? |
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Definition
| Greenish-Yellow, because it is the fluoresence of the lens when seen through the pupil |
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Term
| At what wavelength does 90% of the light begin to transmit for Crown Glass lenses? |
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Definition
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Term
| At what wavelength does 90% of the light begin to transmit for CR39 lenses? |
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Definition
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Term
| At what point does 90% of the light begin to transmit for polycarbonate lenses? |
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Definition
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Term
| How much light is transmitted through a lens assuming no absorption? |
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Definition
| Transmission=I-I(reflected from front surface)-I(reflected from back surface) |
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Term
| What law says that for an absorptive material, layers of equal thickness absorb equal percentages of light regardless of the intensity of the light? |
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Definition
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Term
| Does the color imparted to the lense effect the transmission in tinted solid glass lenses? |
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Definition
| No transmission is only dependent upon the quantity of metal used with crown glass. All wavelengths are transmitted equally. |
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Term
| Do plastic lenses allow all wavelengths through equally? |
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Definition
| No longer wavelengths are transmitted more. |
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Term
| What type of photochromic lense darkens consistently across the lense regardless of prescription? |
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Definition
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Term
| What type of photochromic lenses never wear out, and are not effected by scratches? |
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Definition
In mass
e.g. Corning Sun Sensors and Rodenstock |
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Term
| What type of lense eliminates specularly reflected polarizing light? |
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Definition
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Term
| What materials best polarize light by reflectance? |
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Definition
| Nonconductors called dielectrics such as glass pavement, sand and snow |
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Term
| At what incident angle is light reflected from a dielectric completely polarized? |
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Definition
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