The eye is the organ that allows us to see. The eyeball itself is a sphere spanning approximately 24 mm in diameter. It is suspended in the bony socket by muscles controlling its movements, and is partially cushioned by a thick layer of fatty tissue within the skull that protects it during movement.
You will need to take a blood sample to check your blood glucose levels. You can do this at home using a blood glucose monitor. The most common type of blood glucose monitor uses a lancet to prick the side tip of your finger to draw a small drop of blood. Then you place this drop of blood on a disposable testing strip.
Vision is a broader term than visual acuity or eyesight. In addition to clarity of sight or simply a description of the ability to see, the term "vision" all interactions between the eyes and the brain, and all neurological processes that take place in the brain to make the sense of vision possible.