Which material corresponds to n=1.586 and abbe value 30?

Which material corresponds to n=1.586 and abbe value 30?

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

Answer: (C)

This question tests matching a material’s optical property pair—refractive index and Abbe (dispersion) value. The key idea is that the index tells how strongly a material bends light, while the Abbe number indicates how much the material disperses different wavelengths (lower Abbe means more chromatic aberration). Among common ophthalmic materials, polycarbonate stands out with a high refractive index around 1.586 and a relatively low Abbe value about 30. The other options have either a lower index or a higher Abbe number: crown glass is around 1.5 with a high Abbe near 60, CR-39 is roughly 1.498 with an Abbe around 58, and Trivex is about 1.532 with an Abbe in the low-to-mid 40s. Therefore, the combination of n ≈ 1.586 and Abbe ≈ 30 uniquely points to polycarbonate.

This question tests matching a material’s optical property pair—refractive index and Abbe (dispersion) value. The key idea is that the index tells how strongly a material bends light, while the Abbe number indicates how much the material disperses different wavelengths (lower Abbe means more chromatic aberration).

Among common ophthalmic materials, polycarbonate stands out with a high refractive index around 1.586 and a relatively low Abbe value about 30. The other options have either a lower index or a higher Abbe number: crown glass is around 1.5 with a high Abbe near 60, CR-39 is roughly 1.498 with an Abbe around 58, and Trivex is about 1.532 with an Abbe in the low-to-mid 40s. Therefore, the combination of n ≈ 1.586 and Abbe ≈ 30 uniquely points to polycarbonate.