Ophthalmologist Questions Eye Exam

Why does my eyesight get worse every year?

I have worn glasses for 10 years. I get my eyes checked every year and each time my eyesight is slightly worse. So my lens prescription changes every year. Could it be an underlying problem? What could be causing this?

9 Answers

There are many diseases that can cause the slight loss of vision every year. Have you visited your eye doctor this year?
If you are 40 years old or older, what you have is presbyopia. Your natural lens does not work like it used to. You can get reading glasses. Please check out www.dysfunctionlens.info
If you are younger..near sightedness is a common issue,if middle age..emerging farsightedness begins,if older..cataracts change your focus. See your eye doctor to discuss why he/she feels you are changing.
If you are young and myopic, as long as you are growing your eye will grow and become more nearside. If you are in older age, some changes in your natural lens can happen due to diabetes or cataract.
That's a great question, however it's impossible to answer it accurately without more information about your age and other ocular history. To be safe, my recommendation is for you to be evaluated by a board certified ophthalmologist or optometrist. But I will try to respond in generalities for you.

Assuming you are in your 20s (you say you have been in glasses 10 years), the most common reasons for prescription changes year to year include the natural subtle changes that the cornea undergoes over time, accommodative-state changes as you age, and latent hyperopia. Most people hit a relatively stable prescription in their mid 20s until around the early 40s when they lose the ability to fully contract the ciliary muscle in their eyes that give them that ability to see both far distance and near targets. Latent hyperopes, or farsighted people, actually have a glasses prescription that is able to be corrected for by contracting the ciliary apparatus naturally. So they have perfect vision until they lose enough of that muscle that the distance vision starts to fade. The extent that the ciliary apparatus is contracted is called the "accommodative state". When you get checked for glasses, if your eye is contracting more than usual (you are nervous during your exam or you spent 10 hours studying for a test with your books 12 inches from your face) this will lead to the optometrist or ophthalmologist giving you a prescription slightly different than the prior year. We call this getting "overminused". We are trained to avoid this but it does happen and I can't speak to who checked your eyes this year! And let's not forget about contact lens overwear, contact lens related infections, and contact lens warpage that all can change your cornea year to year leading to changes in your prescription. I could talk about these topics all day long.

Very large shifts in prescription year to year at this age, in general, are not normal and should trigger an exam by a professional. Keratoconus, for example, is a cornea disease whereby the cornea thins and creates an out-pouching leading to high orders of astigmatism and eventually perforation. Premature cataract formation can alter your vision drastically as well, which could be due to excessive UV exposure from snow skiiing, water skiing, or tanning in a tanning bed without protection. Excessive use of systemic steroids like from a steroid inhaler for asthma or triamcinolone creams/ointments from your dermatologist can be other causes. Here in San Diego, "surfers eye" or "pterygia" cause tear film instability and prescription changes annually and eventually require surgical removal. The list goes on and on, so my best advice still remains that you should be seen by an eye doctor to be sure you have ruled the above out. Hopefully this was helpful!

Thank you for your question,

Lee Katzman MD
Cornea, Cataract & Refractive Surgeon
Your eyesight changes over time and review by an optician, optometrist or ophthalmologist may be helpful.
This depends on a number of factors - age, whether you are near sighted or far sighted, the presence or absence of astigmatism, etc.
What is your age? Do you know whether any of these apply to you?
From what you have described, there are 3 main conditions that I can think of:

1. Short-sightedness (myopia) - This condition is when you are able to see clearly up-close, but distance vision is blurry without glasses. If you are in the younger age range, then it can be normal for your lens prescription to change every year as the length of the eyeball changes. It is best to see your optometrist to rule out any other condition, especially if you notice your vision changing. They will refer you to an eye specialist or ophthalmologist, if you require further advice and treatment.

2. Keratoconus - This condition is a progressive eye disease, in which the cornea (front of the eye) becomes thin and bulges forwards. It usually begins in your teens and early twenties but can be diagnosed in a young child, if there is a history of eye rubbing or family history of keratoconus. This can lead to short-sightedness and irregular astigmatism, in which glasses or contact lenses are required to maintain clearer vision. As this is progressive, your optometrist will need to refer you to an ophthalmologist for treatment to stabilize the bulging and prevent further loss of vision.

3. Cataract - This is when the natural lens inside our eyes starts to become hazy and opaque, leading to blurry vision. This most commonly occurs in your fifties, but can occur in the younger age group and continues to progress. Cataracts can cause you to become short-sighted and glasses may be helpful, but only temporarily. Your optometrist may refer you to an ophthalmologist for surgical treatment, if there is significant cataract or angle narrowing which can cause acute angle closure in certain patients. It is best to get a clinical examination.
The most common cause for vision change is dry eye. It could also be related to your age or that you have some type of corneal dystrophy. You would need to be evaluated by an ophthalmologist to know for sure. If you are in the Houston, TX area you can call our office at (713) 558-8777. Thank you!