In 1828, French optician Augustin Fresnel developed apparatus for using the refractive properties of glass in a central lens with concentric prismatic glass rings arranged on vertical panels – the dioptric system. This meant light passing through the central lens could be directed in a beam, but light outside the scope of the central lens could also be bent and captured. The light intensity was greatly increased by the Fresnel lens.
The Chance Brothers in Birmingham, Englandadopted and developed the Fresnel system in their optical systems known as ‘orders’ which classified the size of the lens and the amount of light generated by the light-source. Chance Brothers orders are:
Hyper-radial: 1330mm
Meso-radial: 1125
First order: 920mm
Second order: 700mm
Third order: 500mm
Third order (small type): 375mm
Fourth order: 250mm
Fifth order: 187.5mm
Sixth order: 150mm
Many Australian lighthouses have First Order apparatus in their lantern rooms.

(Source: From Dusk to Dawn, A History of Australian Lighthouses)