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Why is it that in a pair of bifocal glasses the converging lens at the bottom and the diverging lens at the top?
Wiki User
∙ 12y ago
It is a split screen usually the bottom part is cut as the (close up) lens the normal or larger part of the lens is normal- depending on whether one needs primarily distance or close-up correction, or for reading. the bottom lens group is usually secondary, not the main task. Franklin invented bifocal eyeglasses. He also devised the lightning rod, Franklin stove and *Long arm, lever device often used in grocery stores.
Wiki User
∙ 12y ago
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Why did benjamin franklin invent bifocal glasses?
Because he needed them himself. Both his distant vision and his near vision were becoming weaker. He invented bifocals because he was tired of swapping from his reading glasses to his "looking out the window" glasses. He wanted something that combined both of them. To create bifocals, he put half of the lens from his "looking out the window" glasses in the top half of the eyeglass frame, and then half of the lens from his reading glasses into the bottom half of the frames. The combined form became popular and helpful to many people. Of course, he later used shortened versions of these lenses that worked even better. People who are both far-sighted and near-sighted only need one pair of glasses.
Are bifocal contacts easier for men or women to get used to?
These multifocal lenses work a bit differently than conventional contacts do. There are two powers on each contact -- one to correct vision up close, and one for far away. Certain types of bifocal lenses are made very much like bifocal eyeglasses are. This means they have two different prescriptions with the close up vision correction on the bottom and far away vision correction on top with a line separating the two. Other types of bifocal contacts blend the two types of prescriptions together like progressive lens eyeglasses do. Your eye doctor will determine which type of lens is best for you. This does not answer my question AT ALL ! I wasnted to know if it's easier for men or women to get used to bifocal contacts. the reason I ask is that I had absolutely no problem from the first second I got mine but my brother & a male first cousin could not wear them at all. I've heard that the 2 hemispheres of the female brain communicate more than the hemispheres of male brains. I was wondering if that fact accounted for the difference between my experience & that of my male relatives.
Why would you make bifocals?
The inventor of bifocals is Benjamin Franklin. The word can be separated into two parts to understand better. Bi meaning 2, focal meaning to focus. He wanted to be able to see farther away and also be able to read with out switching glasses. top half of the lenses are for nearsightedness to see at a distance, the bottom for reading. so when you look down at your book or paper you wont have to switch glasses or carry around 2 pairs
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What is the defernition for bifocal?
Bifocal is a type of corrective lens. Bifocal lenses are divided into two sections, usually the top for seeing far away objects and the bottom for seeing nearby objects.
Why did benjamin franklin invent bifocal glasses?
Because he needed them himself. Both his distant vision and his near vision were becoming weaker. He invented bifocals because he was tired of swapping from his reading glasses to his "looking out the window" glasses. He wanted something that combined both of them. To create bifocals, he put half of the lens from his "looking out the window" glasses in the top half of the eyeglass frame, and then half of the lens from his reading glasses into the bottom half of the frames. The combined form became popular and helpful to many people. Of course, he later used shortened versions of these lenses that worked even better. People who are both far-sighted and near-sighted only need one pair of glasses.
What is the glasses from the late 50's and 60's called it has a a metal nose rim and the bottom isn't covered with the frame?
Browline glasses
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What are converging parallels in art?
==Converging Parallels == Sometimes used with the term 'vanishing points,' the converging parallels refers to the method of creating the depth of a drawing or painting. You can draw a box and make it perfectly square. If you make the cross line at the top a bit smaller than the bottom one, the box begins to look like it is leaning away from you. So you are drawing what are considered parallel lines, because by definition a box is created of parallel lines, but if you drew the two sides out, they would eventually converge.
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The most efficient way is to use lighter fluid, because it actually eats off the glue that remains once the sticker is gone, but won't ruin your glasses!
Does sakib wear glasses?
well yeah obviously he lives near on manor close in Chadderton near ASDA and best to know is that he opens his glasses and shoves them right up his mums bottom then puts it it in his mouth and his dads. Yo mama's glasses are so thick that when she looks on a map she can see people waving.
Are bifocal contacts easier for men or women to get used to?
These multifocal lenses work a bit differently than conventional contacts do. There are two powers on each contact -- one to correct vision up close, and one for far away. Certain types of bifocal lenses are made very much like bifocal eyeglasses are. This means they have two different prescriptions with the close up vision correction on the bottom and far away vision correction on top with a line separating the two. Other types of bifocal contacts blend the two types of prescriptions together like progressive lens eyeglasses do. Your eye doctor will determine which type of lens is best for you. This does not answer my question AT ALL ! I wasnted to know if it's easier for men or women to get used to bifocal contacts. the reason I ask is that I had absolutely no problem from the first second I got mine but my brother & a male first cousin could not wear them at all. I've heard that the 2 hemispheres of the female brain communicate more than the hemispheres of male brains. I was wondering if that fact accounted for the difference between my experience & that of my male relatives.
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Put ice in the top one.. and put the bottom one in hot water. Top one pops right out!
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These lenses are darker at the top of the lens and get progressively lighter at the bottom. Lightly tinted versions of gradient lenses are used mainly in fashion glasses.
