Final answer:
Cortical cataracts are graded based on the severity of the opacity or cloudiness in different layers of the eye's lens. Ophthalmologists evaluate various characteristics of the cataract to determine the appropriate grade.
Step-by-step explanation:
Cortical cataracts are graded based on the severity of the opacity or cloudiness in different layers of the eye's lens. The grading system typically ranges from 1 to 5, with grade 1 being mild and grade 5 being severe. Ophthalmologists evaluate various characteristics of the cataract, including size, density, and location, to determine the appropriate grade.
For example, a grade 1 cortical cataract may only affect a small area of the lens, while a grade 5 cataract may cover a larger portion and impair vision more significantly.