Which material has the lowest abbe value among Ophthalmic crown glass, CR-39, Polycarbonate, and Trivex?

Which material has the lowest abbe value among Ophthalmic crown glass, CR-39, Polycarbonate, and Trivex?

• A. Ophthalmic crown glass
• B. CR-39
• C. Polycarbonate
• D. Trivex

Answer: (C)

Abbe value reflects how much a lens material disperses light into its component colors. A higher Abbe number means less chromatic dispersion, while a lower Abbe number means more color separation and visible color fringes. Among common ophthalmic materials, crown glass and CR-39 both sit in the high 50s, offering relatively low dispersion. Trivex is a bit lower, in the 40s, but polycarbonate is notably lower, around 30, which means it has the most chromatic dispersion of the group. So polycarbonate has the lowest Abbe value here, trading off some color dispersion for its excellent impact resistance and lighter weight.

Abbe value reflects how much a lens material disperses light into its component colors. A higher Abbe number means less chromatic dispersion, while a lower Abbe number means more color separation and visible color fringes.

Among common ophthalmic materials, crown glass and CR-39 both sit in the high 50s, offering relatively low dispersion. Trivex is a bit lower, in the 40s, but polycarbonate is notably lower, around 30, which means it has the most chromatic dispersion of the group.

So polycarbonate has the lowest Abbe value here, trading off some color dispersion for its excellent impact resistance and lighter weight.