Working out the cause. Nail varnish is one of the most common causes. After painting your nails, the varnish will give off tiny amounts of chemical vapour for a while, even when it feels dry. If you rub your eye, the eyelid skin may react. Artificial nails can cause a similar eyelid reaction.
The PCL (posterior cruciate ligament) is the strongest ligament, or band of tissue, in your knee. It stretches across the back of your knee. It connects your shinbone to your thigh bone and keeps your knee stable. A sharp, violent blow to the knee can stretch or tear your PCL. That can make it hard for you to get around.
An injury to the medial collateral ligament (MCL) is often called an MCL sprain. Ligament injuries can either stretch the ligament or tear it.