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Dr. James
Dr. James, Board Certified Ophthalmologist
Category: Eye
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Experience:  Eye Physician and Surgeon
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It seems there have been different theories over the years

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It seems there have been different theories over the years as to how lens accommodation really works and why its capacity diminishes into older age. (lens elasticity, fluid pressure within the lens chamber, ciliary muscle, drops, etc.)

What is the current theory and what can be done to delay the need for reading glasses?
(e.g. eye exercises, diet, supplements, etc?)

Dr. James :


Dr. James :

The current theory of accommodation is the one proposed by Helmholtz which says that the ciliary muscles contracts which relaxes the lens zonules, allowing the lens to bulge more, thus increasing its power.

Dr. James :

As we age, the composition of the lens changes and causes it to harden.

Dr. James :

because the lens is stiffer, it cannot change shape per the Helmholtz theory.

Dr. James :

The time when the lens stiff enough to not allow for accommodation is sometime during the 40s in most people.

Dr. James :

There are not exercises or medicines that will prevent the lens changes from occurring.

Dr. James :

The lens hardening can happen faster in people who have general poor health, increase UV sun exposure, poor diet.

Dr. James :

So, being healthy with proper nutrition is the best way to delay the loss of accommodation, however, it is something that everyone will have to deal with.

Dr. James :


Dr. James :

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Dr. James :

I am happy to answer any follow-up questions you may have.

Customer: replied 4 years ago.
That is unfortunate, because I have very severe Crohn's disease, at one point not eating for a year. So I have strikes against me in the diet and health categories.

Let me just ask one thing, and this is why I was asking about reading glasses:

I've been using Atropine for a few days now, and trying to determine if I may be far sighted. If a patient with perfect vision is cyclopleged, at what distance would an object begin to be blurry? For me, it seems to be about 28 inches. Or is there a better way I can determine what my plus power might be? (I don't have access to a phoropter)

+2.5 readers give clarity between 10 and 14 inches
+1.25 readers give clarity between 16 and 24 inches

You will need to give me the numbers from your prescription glasses. The information with readers alone is not enough information.
Customer: replied 4 years ago.
I'm not sure what you mean. The question was in reference to a person with perfect vision, so there wouldn't be a prescription.

(I'm asking these questions because I'm needing to figure out my vision correction on my own, as none of the Doctors I've seen have been able/willing to do so.

My current theory is that I'm straining my eyes (adding a plus power) even at distance, and I'm perhaps doing this to compensate for astigmatism and/or because I'm farsighted. As I go through the day, my blurry vision (close and far) increases, and it takes much more effort to fuse the binocular diplopia.

I'm not sure if the accommodative muscles are getting tired, or if they are locking up in spasm. I'm thinking it's the former, because at that point readers are needed for up close, (though strangely they do not help with distance). So this is why I'm trying to determine what my negative power sphere may be.)
Perfect vision does not necessarily mean no prescription.

ASSUMING you had no prescription and your accommodation is zero, +2.5 readers should give you clarity at 40cm (i.e. the inverse of 2.5). +1.25 would give clarity at 80cm.

If the point of clarity is shorter, then you are likely myopic; if it is further away than hyperopic.
Dr. James and other Eye Specialists are ready to help you
Do you have any questions still? Let me know when you will be online again.
Customer: replied 4 years ago.
I posted the new question for you on 4/18 as you requested.
So I have been waiting for you to reply to that.

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