Monday, May 23, 2011

bifocals

1700 AD this day i.e. May 23rd Benjamin Franklin discovered the bifocal lenses.


Bifocals are eyeglasses or contact lenses having two portions one for near reading and one for far vision. This is used to treat Presbyopia.

Presbyopia means “age of sight” when there is a gradual loss of accommodation. It can start as early as 36yrs or as late 50yrs. But usually becomes noticeable in mid forties.

It becomes recognizable as difficulty in reading fine prints begins.

It takes about 1 to 2yrs before treatment is required for before that adjusting illumination or distance helps.

Reading glasses are an option for correcting presbyopia; this is great for people who do not require distance vision correction. Reading glasses are also bought able over the counter without tests thought this is not advisable.

Bifocals requires practise to be used, for the person needs to get used seeing through the proper part of the glass.

From 1700’s ground glass bifocals to today’s seamless ones the bifocals have travelled a long distance.