The earliest form of spectacles, two lenses riveted together, emerged in Northern Italy during the 13th century, though the exact inventor remains unknown. These early spectacles, primarily used for reading, were secured by clamping the nose between the rims. 

Here's a more detailed look at the history of spectacles: 

13th Century:

The earliest form of spectacles, consisting of two mounted lenses riveted together at the handle ends, emerged in Northern Italy.

These spectacles had no sides and were secured to the face by clamping the nose between the rims.

The exact inventor is unknown.

The early spectacles were primarily used for reading, particularly by monks and scholars.

Early Designs:

The original design included a frame to hold the right and left spectacle cell, with a rivet attached to a small strut to hold the two lenses together.

A space was made between them to slide over the nose.

16th Century:

Nose spectacles became more common in use.