comparative range of vision/range of focus

[caren123]

Dear Doctors:
Can you please shed a little bit of light on how the range of vision might differ, i.e.  between monofocal lenses, movovision contacts and glasses? Is there a broader range with one over another?  Is there a "normal" range of vision one can expect with a corrective lens?  Are there correlations with visual accuity, i.e. 20/40, or prescriptive/refractive error?
Thank you.

[JodieJ]

My explanation (above) relates to post cataract surgery vision.  I was in my early 50's when I developed a cataract following retinal surgery.  At that time my vision was corrected for distance with contact lenses, and I wore progressive glasses with a near add of +2.00.  These glasses actually worked fine for me after my distance vision was corrected with IOLs.  (I still wear those glasses sometimes, although the frames have become a little dated.)  So I disagree with your statement about monofocal IOLs being inferior to the natural lens of an aging eye.

Monofocal IOLs provide good vision at one distance only.  Both of my eyes are corrected for distance vision with IOLs, so my intermediate and near vision are blurry without glasses.  Yes, wearing progressive glasses over monofocal IOLs provides excellent vision at all distances.

Yes, monovision with IOLs, refractive surgery, or contact lenses provides the sense of having good vision at all distances.  When I did monovision with contact lenses, I was unaware of my increasing presbyopia.  It seemed as if there was no change in my ability to focus up close.  It was quite a rude shock when I stopped monovision.

[Ray T Oyakawa, MD]

Agree with Jodie.

Dr. O.

[caren123]

Hi JodieJ,
Thank you for your input... Are you saying that with monofocal IOL's, you need to choose which third you want, but with progressive glasses you can have it all come in clear? and with contact lenses you can have one half come in clear  and together get the full spectrum.  If they only provide one third the full distance, then It appears that the monofocal IOL's are quite different-inferior to the natural lens in the eye, even when the natural lens ibecomes less accomodating as we age....

[JodieJ]

Here's a nonprofessional opinion:  Assuming that there are no eye conditions affecting acuity, monofocal IOLs can provide excellent distance, intermediate OR near vision.  Full monovision can provide good vision within about a 2 diopter range (e.g., from plano to -2 D).  This might translate to good distance and intermediate vision and the ability to read everything but the tiniest print.  (According to the professional literature, about 75% of the people can adjust to full monovision.)  Modified monovision would involve a smaller range of very good vision.  Progressive glasses can provide excellent vision at all distances.  Yes, refractive error and acuity are correlated.