Resultats cercant per
categoria Optics
08-06-2012 (1799 lectures)
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Presbyopia is the normal loss of near focusing ability that occurs with age. Most people begin to notice the effects of presbyopia sometime after age 40, when they start having trouble seeing small print clearly — including text messages on their phone.
You can't escape presbyopia, even if you've never had a vision problem before. Even people who are nearsighted will notice that their near vision blurs when they wear their usual eyeglasses or contact lenses to correct distance...
08-06-2012 (1453 lectures)
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Presbyopia is the normal loss of near focusing ability that occurs with age. Most people begin to notice the effects of presbyopia sometime after age 40, when they start having trouble seeing small print clearly — including text messages on their phone.
You can't escape presbyopia, even if you've never had a vision problem before. Even people who are nearsighted will notice that their near vision blurs when they wear their usual eyeglasses or contact lenses to correct distance...
08-06-2012 (1278 lectures)
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Un frontofocòmetre o lensòmetre (en anglès:lensometer), és un instrument òptic per a la determinació del centre òptic i el mesurament de la potència d'una lent oftà lmica, aixà com la direcció de la component cilÃndrica.[1][2]
S'utilitza per marcar les lents oftà lmiques abans de tallar-les, d'acord amb la muntura. Disposa d'unes plomes per poder marcar el centre òptic i la direcció de...
08-06-2012 (1241 lectures)
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Presbyopia is the normal loss of near focusing ability that occurs with age. Most people begin to notice the effects of presbyopia sometime after age 40, when they start having trouble seeing small print clearly — including text messages on their phone.
You can't escape presbyopia, even if you've never had a vision problem before. Even people who are nearsighted will notice that their near vision blurs when they wear their usual eyeglasses or contact lenses to correct distance...
02-10-2010 (555 lectures)
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En òptica, un cercle de confusió és una taca òptica causada per un con de raigs de llum d'una lent que no arriba a un enfocament perfecte a l'hora d'imaginar una font puntual. També es coneix com a disc de confusió, cercle d'indistinció, cercle de desenfocament o punt de desenfocament.
En fotografia, el cercle de confusió (CoC) s'utilitza per determinar la profunditat de camp, la part d'una imatge que és acceptablement nÃtida. Sovint s'associa un valor està ndard de CoC a cada...