should I go for an enhancement?

[DocH]

Hello all,
My Right eye was about -6 and was corrected to -1.75 in June and really hasn't varied since... I have had ++ problems with dry eye but it really hasn't affected my vision in that eye.
So I am wondering about an enhancement. I think I will be OK with mono vision if my R eye is corrected so I can use my dominant L eye for near/mid vision (yes Glenn I am planning on trying a contact lens in that eye first)
My question(s) are
1) should I do it?
2) should it be lasik or PRK?
3) Are the risks for enhancement surgery much higher than the first?
4) If he 'overshoots' and I end up hyper in that eye will it matter if I'm not using that eye for close stuff?

[LasikExpert]

(yes Glenn I am planning on trying a contact lens in that eye first)

Am I that obvious, or is it that I'm that consistent!

You stated that you are left eye dominant. Please take a look at our eye dominance test.

1) should I do it?

Only you can decide if the relative risk is worth the relative gain. You appear to be aware of the issues with the sudden need for reading glasses after Lasik and monovision as a workaround to presbyopia.

2) should it be lasik or PRK?

This depends upon the recommendation of the surgeon. Both are likely appropriate.

3) Are the risks for enhancement surgery much higher than the first?

A flap lift will increase the probability of epithelial ingrowth, but that is normally a benign problem that can be successfully resolved. Vision recovery after PRK on the Lasik flap will be slow compared to vision recovery after Lasik enhancement.

4) If he 'overshoots' and I end up hyper in that eye will it matter if I'm not using that eye for close stuff?

It will matter hugely. Hyperopia (farsighted, longsighted) is more challenging to correct than myopia (nearsighted, shortsighted). The combination of hyperopia and presbyopia commonly results in poor vision quality at all distances. Near vision would undoubtedly be nearly impossible and distance vision would be likely poor. If there will be an error, err on the side of myopia. Myopia would reduce your distance vision clarity, but would improve your near vision in that eye.

[DocH]

You wrote
It will matter hugely. Hyperopia (farsighted, longsighted) is more challenging to correct than myopia (nearsighted, shortsighted). The combination of hyperopia and presbyopia commonly results in poor vision quality at all distances. Near vision would undoubtedly be nearly impossible and distance vision would be likely poor. If there will be an error, err on the side of myopia. Myopia would reduce your distance vision clarity, but would improve your near vision in that eye.

But Glenn surely I wouldn't need good near vision in that eye if I'm doing the monovision thing would I?

[LasikExpert]

But Glenn surely I wouldn't need good near vision in that eye if I'm doing the monovision thing would I?

Correct. What you need is good distance vision in your dominant eye. That means reaching plano (no refractive error). Hyperopia would make distance, near, and intermediate vision of a poor quality. Myopia would make distance vision less than excellent, but near and intermediate vision would still be good. This is why an error on the side of myopia is better than an error on the side of hyperopia, but no error would provide what you seek.

[DocH]

Glenn,
I thought they liked to go a bit on the + side so that as you regress you go through plano
Also why is it important to have good distance vision with your dominant eye?

[LasikExpert]

Glenn,
I thought they liked to go a bit on the + side so that as you regress you go through plano
Also why is it important to have good distance vision with your dominant eye?

Deliberate Lasik overcorrection can be an appropriate method to resolve anticipated regression and may be appropriate in your situation.

Monovision is the process of one eye being corrected for near vision (myopia) and the other eye being corrected for distance vision (plano - no refractive error). Normally the dominant eye is distance vision and the non-dominant eye is near vision. In successful monovision, the brain learns to combine the two to create adequate vision quality at all distances.

All distance vision depends upon the dominant eye being fully corrected. If it is less than excellent, then all distance vision will suffer. The dominant eye being fully corrected to plano is very important in monovision.

Hyperopia in patients with presbyopia causes poor vision quality at all distances. If your dominant eye is made hyperopic, you are not just farsighted. You would have poor vision quality at all distances seen with the dominant eye. Since in monoision 100% of your distance vision is with the dominant eye, your distance vision will be poor in all conditions.

[DocH]

Hi Glenn,
I mentioned monovision to my eye doc and he said (when my eyes were stable) he would correct my dominant eye (just like you stated).

I did the dominant eye test and I use my L eye all the time.

However to try the monovision thing I removed my eye glass lens from my L eye (ie I would be correcting my non-dominant eye).
My brain seemed OK with that. I tried it the other way and I couldn't make my brain use my R eye for near distance and in fact I just seemed to be using my L eye 100% which was great for distance but terrible for close work.

Am I just weird?

[LasikExpert]

Eye dominance and monovision acceptance vary from person to person. I have known individuals who did fine with "reversed" monovision. This is why you try it with contact lenses first. See what works for you.

[DocH]

Dear Glenn,
and the difference between contact lenses and me removing my glasses lens would be....?

[LasikExpert]

...significant. Glasses minimize images. Think of it this way; your entire peripheral vision must fit into the width of the spectacle. To achieve this, everything must be minimized. The minimized image in one eye with a lens and the unminimized image in the other creates an effect called [url]http://www.usaeyes.org/lasik/faq/lasik-aniseikonia.htm]aniseikonia[/url], that can provide poor vision quality and other negative consequences.

Few spectacle lenses provide full correction at all angles of view. They provide the most correction in the center of the visual axis looking straight forward, and then correction is diminished out to the periphery. Astigmatic correction is almost impossible to correct at all angles of visual axis with spectacles. A contact lens corrects the entire visual field of the eye. Additionally, that correction follows the eye and is not subject to the variable correction across the average spectacle lens.

There is a mechanical advantage to the optics of spectacles that helps with near vision. A very slight difference in the distance of the spectacle of the eye can create a myopic shift that provides better than normal near vision.

Monovision with spectacles will not provide the same effect as monovision with glasses.

[ToolBoy]

I'm going in the 3rd week of January DocH, for enhancement of the left. It regressed to -1.5 diopters, while the right stayed plano. And I didn't even shoot for monovision...

I hope they can lift the laser made flap after 11 months.

[LasikExpert]

I hope they can lift the laser made flap after 11 months.

Lasik flaps heal, but not like a cut on your arm. The seal tightly at the edge of the flap, like a Tupperware lid. Once this edge seal is broken by the surgeon, lifting the flap should not be too difficult.