Refractive index of ophthalmic lenses
The refraction index of the opthalmic lenses determines the thickness of the lens based on the gradation of the same.
For several years now, the most used lenses are made of material
organic / unbreakable.
The most used refraction indices are 1.50-1.56-1.60-1.67 and 1.74.
From this it can be deduced that the greater the refractive index of the lens, and lower will be the thickness of it.
Comparison between the lens thicknesses and the refractive index of the different organic materials used for the construction of ophthalmic lenses
How to choose the appropriate index of your lenses
The choice depends mainly of the your correction
Mild correction from -2 a +2 : index 1.50
Average correction from -4 a +4 : index 1.60
High correction from -6 to +6: index 1.67
Very high correction above 6: index 1.74
Important: If you are not sure you have made the right choice,
do not hesitate to contact us at the email address