Final answer:
Unilateral cataracts are typically isolated sporadic incidents, occurring without a regular pattern and usually in one eye, not necessarily linked to systemic causes.
The correct answer is option D) Isolated sporadic
Step-by-step explanation:
Unilateral cataracts are usually isolated sporadic incidents. This means they occur on one side and without a regular pattern or predictability. Factors contributing to the development of unilateral cataracts can include injury to the eye, certain diseases, or could be congenital.
It's important to note that while cataracts are often thought of as a condition affecting both eyes symmetrically, this is not always the case, as seen with unilateral cataracts.