The optic nerve is the nerve that connects the eye to the brain and carries the impulses formed by the retina to the visual cortex of the brain. The choroid is a thin vascular layer between the sclera and the retina that supplies blood to the retina and conducts arteries and nerves to other structures in the eye.
A muscle pull (or strain) occurs when you twist, pull, or tear your muscle or tendon, the strong elastic cord that connects your muscle to the bone. As we age we are more susceptible to muscle pulls. However, you risk a pull if you donât warm up properly before you exercise and stretch a muscle past its limit, train longer than what your body can handle, or if you push a past muscle injury too far before the muscle has had adequate time to heal.
How Is a Strain Different From a Sprain? Even though both can hurt a lot, strains are not as serious as sprains. Because a strain is pain in the muscle, it may start to hurt immediately or several hours later. The area will be tender, feel sore, there may be some swelling, and it might also appear bruised. A sprain will probably start to hurt right away.