| trifocal |
lenses have three different focus areas: the top for distance vision, the center for intermediate vision, and the bottom for near vision. Although bifocal lenses usually are designed so that the line of division is at the level of the lower eyelid, trifocals are fitted higher, with the top line of the middle region at the level of the pupil.
출처: www.visionrx.com/library/enc/enc_prescglasses.asp
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| trifocal g. |
glasses with trifocal lenses.
출처: www.mercksource.com/pp/us/cns/cns_health_library.j...
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| trifocal l. |
one having three segments with different refractive powers, ordinarily with the upper for distant, the middle for intermediate, and the lower for near vision; used in trifocal glasses.
출처: www.mercksource.com/pp/us/cns/cns_health_library.j...
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| trifocal glasses |
Glasses with three different corrections in each lens: one each for near, intermediate, and far vision.
출처:
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| trifocal |
a lens that has three different prescriptions in the same lens (distance, intermediate, and near).
출처: www.douglaswilson.org/ocular_definitions.html
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