Answer:
Not enough information is given but my mom is in the medical feild and she says that a condition common with age is presbyopia. It causes the leanses in your eye to become less flexable and less able to thicken therefore less able to focus on near by objects. Another is catteracts which I assume you already know about so I will not explain.
Explanation:
Swelling is a sign because when you swell up then you know theres something wrong
Scalene a right triangle is a scalenece triangle
