Final answer:
The cornea acts as a converging lens with a focal length of approximately 2.3 cm, and its approximate focusing power is 43.48 diopters. This significant power accounts for about two-thirds of the eye's total ability to focus light.
Step-by-step explanation:
The focusing power of the cornea in the human eye is significant and responsible for most of the eye's ability to focus light. The cornea acts as a converging lens with a focal length of approximately 2.3 cm. To find the optical power, which is the reciprocal of the focal length (in meters), we can use the formula P = 1/f, where P is the power in diopters (D) and f is the focal length in meters. Since the focal length of the cornea is given as 2.3 cm, which is 0.023 meters, the power of the cornea can be estimated as P = 1/0.023, which is approximately 43.48 D. As the cornea provides about two-thirds of the eye's total refractive power, it is clear that the cornea is the primary structure for focusing light onto the retina, with the lens providing finer adjustments.