The eye lens is acted upon and controlled by a muscle which is called the ciliary muscle and also by a process, which is called the ciliary process. The muscle and process contract to give the eyes nearer vision. They relax and, more or less, stretch, for farther vision. The eye lens, the muscle and the process are located inside the eyes. It is important to emphasize that the mechanism which changes the focus for near and far seeing is located inside the eyes.
In the optical language, the bending of the eyes for nearer seeing is called "Accommodation." This is a term which is meaningless and misleading. It is meaningless because it gives you no clue as to how or what it does. It is misleading because it assumes and makes one believe that it is effortless. On the contrary, the bending of your eyes for nearer seeing, like the bending of your body, is a work of action. Often it takes lots of effort and consumes lots of energy for nearer seeing.
Unlike the camera, the adjustments of the eyes for far and near seeing is a one-way adjustment. The natural rest position for the eyes is when the mechanism assumes the position of least curvature for the eye lenses, and the least contraction for the ciliaries. This position is afar-away focus position. Our eyes are unable to see nearer objects clearly without bending and assuming a higher curvature.