If you ever study the mechanics of an old-fashioned camera, you’ll notice that much of the interior is made up of empty space. This is because a camera uses a lens to focus light onto a plane of special photo-sensitive film, and for that image to be clear, there needs to be a very specific distance between the lens and the target. The anatomy of the eye works much the same way, with a flexible lens at the front of the eye focusing incoming light onto the light-sensitive cells that line the retina at the back. But the eye does not have a rigid outer structure like a camera, so it needs to be filled with a fluid that is clear enough to allow light to pass through, but that supplies enough internal pressure to maintain the eye’s shape. This is where the aqueous and vitreous humors come into play. These fluids are extremely important, and any problems with them can potentially have serious adverse effects on your vision.
Inside the eye are several compartments, or chambers. Two of those chambers, the anterior (between the cornea at the front of the eye and the iris) and the posterior (between the iris and the lens) are filled with a thin, watery fluid called the aqueous humor. After being produced by the ciliary body, the fluid flows through the pupil to fill the anterior and posterior chambers, after which it drains out of the eye through a structure called the trabecular meshwork. If the ciliary body produces too much, or if the trabecular meshwork does not allow the fluid to drain quickly enough, the internal pressure in the eye will increase. If it is left untreated, this high eye pressure (called ocular hypertension) can potentially lead to glaucoma, a serious condition that can cause permanent vision loss in some individuals.
About eighty percent of the space inside the eye, the area behind the anterior and posterior chambers and between the lens and the retina, is filled with a clear, gel-like substance called the vitreous humor. Consisting mainly of water, with small amounts of collagen, proteins, salts, and sugars, the vitreous has a firm, jelly-like consistency and helps to maintain the eye’s spherical shape. As we age, the vitreous gradually becomes more liquid and starts to shrink, pulling away from the retina and the inner walls of the eye. Small fibers that were previously attached to the retina separate and float freely in the vitreous humor, casting shadows on the retina. These shadows are called eye floaters because they look like dots, dust, cob webs, or strings floating in your vision, but they are generally nothing to worry about. More seriously, it is possible that the vitreous detaching from the retina can create a small tear in the surface of the retina itself. Even the smallest retinal tears need to be treated promptly, either with lasers or cryotherapy, because if vitreous fluid seeps through the tear it can cause the retina to pull away from the tissue around it, like damp wallpaper peeling away from the wall. This is called a torn or detached retina and can cause permanent vision loss.
Problems with the aqueous or vitreous humors are potentially very dangerous because there are few early warning signs. Patients generally do not notice any serious symptoms until damage has already begun. That is why it is no important that you come in to Georgia Eye Physicians and Surgeons for comprehensive medical eye exams on a regular basis, particularly if you are over the age of fifty when vitreous disorders become more common. If you have any concerns about your vision, or any questions about how to best maintain the health of your eyes, please contact Georgia Eye Physicians and Surgeons to schedule an eye exam with Dr. William Segal or Dr. Marc Lay. Be sure to follow us on Facebook, Twitter, and Google+ for more information on how to keep your vision clear and healthy.