Final answer:
Graded index (GRIN) lenses possess a tapered base curve, crucial for correcting aberrations and providing precise focus, especially in high-end optics like endoscopes and camera systems.
Step-by-step explanation:
Lenses with a tapered base curve are often referred to as graded index (GRIN) lenses. These specialized lenses feature varying refractive indices, which allows them to provide a more precise focus and correct for aberrations more efficiently than lenses with a uniform refractive index. GRIN lenses are crucial for applications like endoscopes and advanced camera systems.
In the case of thin-lens approximations, the lens thickness is much less than its radii of curvature; therefore, light rays essentially bend at the lens center. For abberation correction, lenses may possess specially shaped surfaces rather than simple spherical ones. Multiple lens elements and varying refractive indices come into play to make these corrections possible.