Free Vision Screenings for Infants and Toddlers. The early years of life from birth until age five are crucial for a childâs visual development and eye health. The American Optometric Association recognizes how important it is to get your baby's vision off to a good start.
atrium(Noun) An upper chamber of the heart that receives blood from the veins and forces it into a ventricle. In higher vertebrates, the right atrium receives blood from the superior vena cava and inferior vena cava, and the left atrium receives blood from the left and right pulmonary veins.
noun. 1  The definition of an atrium is a body cavity, specifically relating to the heartâs chambers which take in blood. When a person has open-heart surgery to repair a blockage in an artery which gives blood to the heart, it is an example of surgery on their atrium.