Young's modulus of elasticity

modulus of elasticity

The ratio of a force applied to a material to the increment of change (e.g. increase in length; angular deformation) in that material. Materials with low modulus of elasticity are less resistant to stress, while materials with high modulus of elasticity resist stress and hold their shape better. The SI unit of modulus of elasticity E is the pascal (Pa). Examples: the modulus of elasticity of a PMMA contact lens is about 3000 MPa, it is around 0.4 to 1.5 MPa for silicone hydrogel lenses and 0.3 to 0.5 MPa for hydrogel lenses. Syn. coefficient of elasticity; Young's modulus of elasticity.

Millodot: Dictionary of Optometry and Visual Science, 7th edition. © 2009 Butterworth-Heinemann