Mostly for bank clerks ....
Bifocals are glasses which have two focal points, one for near objects (reading) another for far away things.
Older, "true" bifocals, have a separation line in the lens.
New "varifocals" can habe more than 2 focal areas but need time to get used to ;-)
they were made out of metal
they were made out of metal
1783 and was made until now
No, George Washington did not invent bifocals, but he is often credited with popularizing them. The invention of bifocals is attributed to Benjamin Franklin, who created them in the 18th century to address his own vision issues. Washington, however, was known to have used bifocals later in life, and he had a pair made for himself by an optician.
ben Franklin invented his bifocals at his house in philly and made them on March 23.1784
they were made in 1784 he didnt actuallly counstruct it a man in France or London did it for him
Please help me find my bifocals.
because bifocals are still used today and without bifocals you would have to have 2 pairs of glasses that's why its Important
bifocals changed in size, shape, and magnification.
Bifocals.
* lightning rod * Franklin stove * odometer * bifocals* lightning rod * Franklin stove * odometer * bifocals* lightning rod * Franklin stove * odometer * bifocals* lightning rod * Franklin stove * odometer * bifocals* lightning rod * Franklin stove * odometer * bifocals* lightning rod * Franklin stove * odometer * bifocals
Bifocal lenses as a concept were not patented; there are dozens of patents related to bifocals, bifocal contacts, and processes to make bifocals.