During most of this period, eyeglass frames were individually handmade and newer models appeared in quick succession. The guidelines below represent the period of common use of these design elements, however they are not all-inclusive. Much remains unanswered so this should only be used as a guide. It is based on personal experience as well as reflecting much of the current literature. Additional ideas and comments are welcomed.

Realize that all pre-1725 spectacles had round frames with a bow or C bridge, no sidearms, and therefore no finials.

(Click on any of the pictures on this page to display a larger image.)

FEATURES	EXAMPLES				PERIOD OF COMMON USE
LENS design
Round lenses					pre-1725 - 1820
Visual glasses (Martin's Margins)					early 1760's - 1820
Oval lenses					around 1790 - 1900
Four lenses (Richardson)					1815 - 1900 (most found are octagonal 1860s)
Rectangular and Oblong lenses					1835 - 1890
Octagonal lenses					1835 - 1880
BRIDGE design
"C" bridge					pre 1750 - 1840
"K" and "X" bridge					1810? - 1900
"Crank" bridge - upside down "U" in the U.S. "Arch" bridge in the U.K.					after 1835 - 1880
scroll bridge					1870? - 1900
"W" bridge (saddle)					1885 - after 1900
TEMPLE design (Side arms)
Short wide temple with large ring finials (earliest examples had Scarlett spirals)					1720s - 1840? (possibly as early as 1714)
Double hinge (Ayscough)					1760 - 1820
Turn-pin style (pivot)					1800? - 1900
Pin-in-slot (wide-telescopic)					1815 - 1860 (narrowing during this period)
Long straight					1850 - 1900
Loop slide (narrow telescopic) - in the U.S. "figure of eight" in the U.K.					1840 - 1890
Curl temples (riding bow)					1885 - after 1900
TEMPLE Finials (endings)			There are many variations of temple finials
Large rings					1740 - 1810
Small rings					1810 - 1830 (only seen on wide telescopic)
Teardrop loops					1790 - 1900 (generally grew smaller during this period)
Interesting Variations
	Amber colored shooter's lenses	Decorated brass temple spectacles with frosted lenses		Skull fit	Unknown