Which lens material has the lowest Abbe value among the following?

Which lens material has the lowest Abbe value among the following?

• 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 colors, i.e., chromatic dispersion. A higher Abbe value means less color fringe and sharper perception of edges, while a lower Abbe value means more chromatic aberration. Among typical lens materials, polycarbonate has the lowest Abbe value, commonly around 30, which makes it more prone to color dispersion and fringing. The other materials listed have much higher Abbe values— crown glass and CR-39 are in the upper range (roughly the high 50s to low 60s), and Trivex sits in between but higher than polycarbonate. So polycarbonate is the material with the lowest Abbe value.

Abbe value reflects how much a lens material disperses light into its colors, i.e., chromatic dispersion. A higher Abbe value means less color fringe and sharper perception of edges, while a lower Abbe value means more chromatic aberration.

Among typical lens materials, polycarbonate has the lowest Abbe value, commonly around 30, which makes it more prone to color dispersion and fringing. The other materials listed have much higher Abbe values— crown glass and CR-39 are in the upper range (roughly the high 50s to low 60s), and Trivex sits in between but higher than polycarbonate. So polycarbonate is the material with the lowest Abbe value.