Why is my eyesight getting worse?
Hundreds of thousands of people over many centuries have dedicated their lives to answering this question. There are specialists and sub-specialists in ophthalmology, neuroscience, chemistry, physics, and many other fields that dedicate their lives to developing medications, products, devices, and techniques to improve vision. If your vision is getting worse, the bottom line is you must see an eye doctor to begin the process. Don’t self-diagnose and wait for it to get better. See an eye doctor! It’s essential, because if you say to yourself “my eyesight is getting worse“ or asking “why does vision get worse“ or “why does my eyesight keep getting worse“ then you may be experiencing something that is progressive and easier or even possible to fix if you get it taken care of now. Do not wait!
Although the answer to “vision getting worse“ or “why does eyesight get worse“ and eyesight deterioration or eyesight worsening could take up entire libraries, I will try to summarize it in 1500 words or less.
I think perhaps the best way to go over the many reasons why your eyesight may be getting worse is to work from front to back anatomically so that you can realize how many thousands of different potential reasons there are for why your vision gets worse.
First of all is that your vision is related to the entire health of your body. Thousands of systemic diseases can affect your vision. The most common causes include diabetes, alcoholism, obesity, genetics, trauma (and risky dangerous behavior) and others. Each of these if controlled can maintain your eye health as well as the rest of your body health much better if you take care of your general health. There are other health problems such as connective orders like rheumatoid arthritis, lupus, psoriatic arthritis, that can affect your eye health.
Anatomically, we will go from:
- Lids and lashes/skin
- Lacrimal system: dryness and tear production
- Vitreous and inflammatory disorders
- Optic nerve
- Vascular system
To begin with, we will discuss the disorders of the eyelids. Your eyelids and lashes are very important to the health of your eyes. The lashes protect your eyeballs by collecting dust and other foreign objects and prevent them from going into your eyes. Without lashes you would get more foreign bodies, dust, and dirt in your eyes. Your eyelids obviously protect your eye surface, but they also help by rewetting them and cleaning them thousands of times per day. They keep the surface lubricated and healthy. Disorders of the eyelid skin can include everything from skin cancer to lupus Which can affect the health of your skin and therefore affect your eyelid’s ability to protect the surface of your eyes. There are many things that can affect the surface of your eyes. Keep this part healthy and you will protect your eyes and therefore they will feel better, see better and last longer.
The lacrimal system (produces and distributes the healthy healing tear film): this is closely related to your eyelids but is not the same. The surface of your eyes is constantly rewetted by a mucus layer, a water layer, and an oil layer. If any one of the three layers is deficient, then you may have a disruption in the ocular surface (the surface of your eyes). This can make your vision foggy, blurry, and fluctuate. It’s common after Lasik or PRK surgery to have some dryness for several months after the procedure and have vision foggy and fluctuate for that first few months. This demonstrates that the surface of your eyes is very important for a good clear vision. Fortunately it does recover to baseline after Lasik or PRK surgery, but if you have dryness prior to the surgery you will have dryness after the surgery. One extremely beneficial part of Lasik surgery is that it allows you to go without contact lenses which also may adversely affect the surface of your eyes and cause irritation, itching, redness, and inability to wear contact lenses. One great reason of many to have LASIK or PRK eye surgery!
The next level is your cornea, the clear window on your eye that is a curved spherical shape. The cornea is clear and must remain clear and polished with the tear film. Each anatomic layer is dependent on the one previous to it as you can see. The cornea health is dependent on your lacrimal health which is dependent on your eyelid health. The cornea’s main job is to focus the light so that it goes back to the retina and focuses perfectly on the back of your eyes so that you see a clear image. This is where Lasik and PRK come in. If you wear glasses, you do not have the proper corneal focus/curvature. LASIK and PRK change the curvature to allow you to see clearly without glasses. Amazing and successful. There are many many disorders of the cornea (many text books have been written on the subject!). Anything that affects the clarity, curvature of your cornea can adversely affect your visual health. There are many fewer corneal transplants performed now than there were a generation ago because eye surgery techniques have improved, but it’s still done, and still an amazing procedure.
Going a little further back we arrive at your iris, which is the colored part of your eye. In the middle is a circular opening called the pupil. This opening regulates the amount of light allowed in your eye. It also helps to focus the light. Any disorder of your pupil can affect your vision as well. Too much light causes extreme light sensitivity. Too little light may decrease your vision in dim or dark environments. There are many disorders that can adversely affect your pupil and iris.
If we go one level further back in the eye we arrive at the natural crystalline lens. This is an amazing structure that can change shape to focus light differently depending on the distance of the object to your eye. The more it focuses, the clearer you will see for near objects. This flexibility decreases with age, which is why people have difficulty seeing near objects at about age 45 and need reading glasses. This “vision getting worse” reason happens 100% of the time. The lens of your eye is the number one reason for decreased vision in the world today. It gets cloudy with age. Typically some time in our 60s and 70s, the clarity of your natural lens decreases to the point where you decide to have cataract surgery. Cataract surgery is performed over 4 million times per year in the United States. Cataracts occur when the lens of your eye becomes clouded. It is a spectrum of slow- declining vision typically, although there also can be more rapid variations of cataract that form more quickly. Each type of cataract is treated with cataract surgery in which the natural crystalline lens is removed and an artificial lens is placed in its position. Currently we can not only give you a clear lens, but choose a lens that will allow you to focus your world clearly without any glasses. In the recent 10 years prior to this writing there have been numerous developments in multifocal lenses that allow you to not only see distance vision perfectly but in your near vision as well. It is getting more and more amazing! Lasers are used to assist the surgeon with the surgery performing the incisions and breaking up the cataract with only the use of a laser. Pretty exciting! This is by far the number one cause of eyesight deterioration in older Americans.
As we go a little further back in your eyes there is a normally clear gelatinous substance called the vitreous that fills our eye cavity behind the lens of your eye but in front of the retina. The vitreous undergoes degeneration throughout our lives that most people experience as floaters. One of the bad things vitreous can do is pull on the retina, tear it and therefore cause it to detach which is another reason for decreased vision. Remember my first paragraph where I said get it checked out as soon as possible!? Do not wait, because if you have a retinal detachment, time is of the essence. Delaying it could lead to a much worse outcome. The vitreous can be completely removed by a retinal surgeon with no ill effect. You can see just fine without your vitreous. The space will fill up with the normal fluid but without the strands of collagen that can cause floaters.
There are inflammatory disorders of the vascular system of the eye. These are typically grouped together as a term called uveitis. The uvea consists of the choroid (the blood vessels within the retina) the ciliary body (the muscular system that regulates the lens of the eye and produces fluid to fill the eye) and the iris as described above. Many systemic inflammatory disorders can affect the uvea and cause it to become inflamed. This is potentially blinding also. Also a huge amount research and dedication to improving this condition exists.
If we move a little further back in the eye we arrive at the retina. The retina has at least 11 described layers and many sub-layers within each of those. The retina is an amazing tissue. Also called the neurosensory retina, it takes light energy, converts it into cellular energy, modulates it, sends it in an organized pattern through the nerve cell layer, optic nerve, and optic tract where it arrives in the visual cortex of the brain, and is interpreted to allow us to navigate our world. Totally and unbelievably miraculous. Words can’t express my amazement about how wonderful and amazing the retina is. Like in any complex system however, the retina can be affected with myriad problems. One of the most perplexing and upsetting is called age-related macular degeneration or ARMD. This is the most common cause of legal blindness in the United States in patients over 65 years old. It consists of an accumulation of deposits in the retina that damage it and distort, and limit vision often to the point where a patient cannot clearly see faces, read or drive. It’s potentially devastating, but the treatment of macular degeneration has improved drastically with the advent of medications that can slow or stop the progression of macular degeneration.
The second biggest cause of legal blindness in the United States is glaucoma. Glaucoma is a condition whereby the optic nerve degenerates generally over a long period of time. But once the nerve is gone, it’s never coming back, so don’t lose nerve fibers if you can help it-and you can, by getting an eye exam! There are many variations of glaucoma, but the most common is called “open-angle glaucoma“. Open-angle glaucoma consists of a progressive neuropathy whereby the fibers of the optic nerve die over a period of time. It also can be treated in number ways with eyedrops, laser, and surgery. Improvements in glaucoma treatment have been made continuously over the past hundred years, but it still remains a perplexing and difficult chronic disease to manage.
Vascular issues also can severely affect vision. Blood clots, fatty deposits, ruptures of blood vessels, aneurysms, and mini-strokes can damage or decrease vision substantially. All the things that we normally recommend such as control of diabetes, hypertension, obesity, and good general health can reduce the risk of you experiencing vascular problems of the eye.
As you can see there are many many causes that can answer the question why your vision is getting worse or eyesight getting worse. But the take-home message is this: get your eyes checked now if you think you’re having a problem. And get your eyes checked annually if you don’t think you’re having a problem. Many of these conditions can be cured or successfully managed for the rest of your lifetime without you losing your most precious sense: vision is an inexpressibly complex and wonderful thing. Do not take it for granted – get your eyes checked.
-Dr. Matthew Sharpe