Optical glasses will be found in scientific instruments, microscopes, fighter aircraft and most commonly in spectacles.
The most important properties are the refractive index and the dispersion:
- Refractive index is a measure of how much the glass bends light.
- Dispersion is a measure of the way the glass splits white light into the colours of the rainbow.
Glass makers use the variations in these characteristics to develop optical glasses.
In this Section
Many glass making terms have entered the language: 'Shut yer gob': a molten lump of glass is called a 'gob' to which the glass blower attached a tube to blow the glass into shape. The blower had to blow hard which made his cheeks very large. Today someone with a big mouth is told they have a big gob.