Final answer:
The question about cataract coverage on the circumference of an eye's lens does not match the provided information on cataracts and their effects on vision in Physics. The reference materials discuss spectacles prescribed after cataract surgery but do not provide data on proportions of cataract coverage.
Step-by-step explanation:
Based on the information provided, none of the options presented directly answer a question regarding the proportion of a cataract's coverage on the circumference of an eye's lens. Instead, the reference materials focus on the effects of cataracts on vision and how removing the cloudy lens affects the eyes' refractive power, necessitating the use of a strong spectacle lens to correct vision. Moreover, the provided fractions seem to relate to an entirely different context, possibly exponential growth in a different subject matter. Therefore, it's not possible to give a definitive answer to the question as stated because it does not seem to correlate with the understanding of cataracts from a Physics standpoint. The removal of a cataract-affected lens from the eye typically leads to the prescription of a spectacle lens usually around 16 D, compensating for the loss of the eye's natural focusing power.