How The Eyes Work

Have you ever heard the adage that we don’t see with our eyes, “we see with our brain”? Well, it’s true. The eyes are responsible for transmitting images to the brain, by focusing on an object and understanding what the object is. It is the shape and size of your eye that determines whether our eyes are able to focus on an object, or if corrective ophthalmic lenses are necessary. When your eye focuses on an object, an image is formed. The brain then processes the object, projecting a virtual image. Optical scientists rely on our knowledge of eye sight, the brain and how it processes images to design the best possible lenses to correct an individual’s blurry vision.

The Human Vision System is a complex system consisting of two sets of lenses (the cornea and crystalline lens), two sensing devices (retina), and the brain. The Cornea is in the front of the eye and is responsible for focusing on an image. The Crystalline Lens is found in the anterior chamber of the eye, which not only focuses on an image, but adjusts your eyes to see objects far away, or within a short distance as well as close up. Consider when you wake up from a nap and try to focus on an image. Your eyes may have to blink once or twice to actually see a clear image.

The cornea and crystalline lens of the eye both carry a curved shaped, making our eyes appear round. When the cornea and crystalline lens of the eye are of normal size and shape, we see images clearly. If, however, a person’s cornea is too curved or not curved enough, they have a Refractive Error. Simply stated, a refractive error means that there is an error in getting the eye to focus clearly on an image. Ophthalmic Lenses are needed to focus on an object and perceive it clearly. Refractive Errors include Myopia, Hyperopia and Astigmia.

If you are Myopic, Hyperopic or Astigmatic, you will need an ophthalmic lens to assist your eyes to see clearly. If your eyes also need help focusing on images close up, you have a condition known as Presbyopia. This means that your crystalline lens, due to the natural aging process, can no longer focus and adjust your focus as it used to. In this case, additional magnification is needed to focus up close. This additional magnification can be obtained through reading glasses, bifocals, or progressive addition lenses. (Please see “Eyes Over 40” for more information).

Our eyes are considered by many as the most precious of senses. We only get one set, and it is vital that we care for and protect them. No matter what refractive error one may have, clear, uncompromised vision is possible with a great lens. Improvements in science and technology allow lens engineers to recreate vision through lens designs. When it comes to your vision, if you need corrective lenses, insist on the best…insist on Shamir lenses.