Accommodation with the natural lens

The primary function of the eye is to process images by focusing light rays on the retina in the back of the eye.  The cornea, the outermost part of the eye, starts this process, and the transparent natural lens inside your eye completes the focusing process.  The lens is located directly behind your iris (the colored part of your eye) and can change its curvature based on the distance between your eye and the objects you are viewing.  The process of changing the lens curvature is called “accommodation.”

A person is born with a natural lens in each eye that focuses on objects near and far.  The natural lens allows most people under the age of 40 to quickly change their focus (accommodate) from a near object to a far object, or vice versa, without difficulty.  However, as we reach our mid-40’s, the aging process makes the lens less flexible, and the lens slowly loses its ability to shift between near and far images.  This loss of accommodation is called ‘presbyopia,’ and many patients eventually need bifocals or reading glasses to clearly see near objects.

Many older individuals retain a small level of accommodation that allows them to transition from mid-range to distance vision.  However, when your natural lens is removed during cataract surgery and replaced with a traditional intraocular lens, any residual accommodative function is eliminated.  If you’d like to be able to have good near and distance vision without glasses after surgery, then you should explore whether a premium intraocular lenses is the best option for you.