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They provide the convenience of correcting two vision problems - without having to use two separate pairs of glasses. For example, one half of the lens would be used for reading distance, and the other for watching TV.
Wiki User
∙ 10y ago
Wiki User
∙ 16y agoAs one ages, so do the eyes. Gradually one loses some elasticity and the eyeball/corneas becoms less acutely focused. Thus the need for bifocals.
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Can people have bi colored eyes?
Yes it is very possible i have black hair, blue eyes and im fairly tan
How many lenses does the human eye have?
A convex or converging lens is found in the human eye.
What does it mean to be a bi?
"Bi" generally refers to as 2. You are "bi" or both ways. Sexually it refers to someone who likes both genders to have sex with.
How do you know if youre bi?
If you like both boys and girls you're bi-sexual. If you like one or the other and don't like the other of the two genders you're not bi-sexual.
In photosynthesis what waste products are produced?
Actually bi products are formed. Main bi product is Oxygen.
Where can one purchase discount bi-focal glasses?
There are many places where one can purchase discount bi-focal glasses. One can purchase discount bi-focal glasses at popular on the web sources such as eBay and Amazon.
Who invented bi-focal glasses and signed the Declaration of Independence?
Benjamin Franklin
What is the name of those glasses with the lines through them?
They are called "pince-nez" glasses. These glasses do not have arms but instead have a nose clip or pinching mechanism to stay in place on the wearer's nose.
How do bifocals help us today?
Bi means two, focal means to focus, so Bifocal glasses help you with both short sight and long sight.
Why do you have 2 glasses in spectacles?
Because you have two eyes, if you are talking about bi focal lenses then it is so that you can use a single glass both for reading and for outdoor use (looking at objects that are for.
What were some of the inventions created in the 18th century?
Some of the great inventions of the 18th century include the steam engine, the piano, the thermometer, the fire extinguisher, the parachute, bi-focal glasses, the smallpox vacccination, gas lighting, and the battery.
What is the name of the glasses which can focus on two lengths at the same time?
Glasses like this are called bi-focals. Bifocals
What do you call field glasses with two pieces starts with bi?
It is binoculars.
What are the different types of lenses for the eye?
your mom bi-achh!
What Means Bifocal science?
it could be learning something else along with X1 & XII Bi-focal courses are part of the science stream where students can opt for any vocational subject in lieu of the second language, geography and biology. The vocational subjects include computer science; electronics; mechanical and electrical maintenance; scooter and motorcycle repair and civil engineering. Usually, students aiming for engineering degree studies opt for bi-focal courses as it gives them better scoring opportunities. This can be gauged from the fact that bi-focal stream students have traditionally dominated the toppers in the higher secondary certificate (HSC, class XII) exams at state as well as divisional levels. Electronics and computer science rank among the most sought-after bi-focal courses.
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
What things were invented in 1780?
The year 1780 is given as the year that Ben Franklin invented bi-focal eyeglasses and Gervinus invented the circular saw.
