The accommodation reflex (also known as accommodation-convergence reflex) is an automatic reflex of the eye that occurs when you switch from looking at a far away object to one that is closer to you. This reflex is involuntary - you don't have control of it and it happens automatically. This reflex keeps objects in focus even when switching from close by objects to far away ones. Think of a camera - it has to focus (make blurry images sharp and clear) when you move from a far away object to a closer one. Your eye, because of the accommodation reflex, does this automatically.