How can this be???

Dear Dr. Prince,

Your board has so many people that write in regarding the multifocal, or accomodating lens, because they want to see clearly at more than one focal point..
I was told, and have read many times, that a traditional lens has only one focal point.  It can be set to see up close, middle vision, or distance.  Yet, a friend recently told me that her doctor told her that if she did not wear glasses before cataract surgery, all she would need after surgery would be reading glasses.  Yet, I was told I would need bifocals, even though I have never worn glasses before my surgery.  That is why I went with the multifocal.  I was told that things to arms length would be out of focus with a traditional lens.
Now I have another friend that had cataract surgery 2 months ago. She had the monofocal. She can read the smallest print and see perfectly at intermediate and also at distance.  How can this be if the monofocal lens are set for one focus??  She does not have monovision.  And she asked me what I meant by halos.  So, I presently do not know what to believe. She also had astigmaism and yet she can see clearly at all distances without halos with a traditional lens. And it was totally covered by her insurance.  Can you please explain this to me. I would not have even minded wearing reading glasses, which I still do, in bright light, but was told that I would need bifocals.  How can my friend see so clearly at all distances, with a monofocal lens that is not monovision??  Totally confused.

[Forum-OD-MP]

"Yet, a friend recently told me that her doctor told her that if she did not wear glasses before cataract surgery, all she would need after surgery would be reading glasses"

no.  every eye is completely different and every case is different.  you cannot assume that this will work for you.  i dont think that method would work for most people.

"She had the monofocal. She can read the smallest print and see perfectly at intermediate and also at distance. How can this be if the monofocal lens are set for one focus??"

small pupil size is the only explanation i can think of.

for 99.9% of people, a monofocal implant w/o monovision gives good vision at ONE distane if you're lucky.  your friend either has small pupil size or is not that picky about her vision.

[K-D]

P.S. It is not modified monovision either because she has only one eye operated upon. Yet, if she covers her unoperated eye, she can see near, far, and in between with a traditional lens implant in her operated eye.  How is this possible?

[JodieJ]

It sounds like your friend is 20/happy at all distances.  But your friend's actual visual acuity at any distance is unknown.  And the quality of vision that would be satisfactory for some people would be extremely unsatisfactory for others.  A lot depends on life style, vocation, hobbies, interests and what someone's become accustomed to.

People who do not need glasses before cataract surgery do not have significant astigmatism, which blurs vision at all distances.  If their post-surgery vision were set to 20/40 for distance, they could drive without glasses.  Their uncorrected intermediate vision would be great.  They could read menus, most books, and most newspaper print in good lighting.  They'd probably need readers to look up an address in the phone book, thread a needle, or read a menu in a dimly lit restaurant.

But most people would prefer to have 20/20 vision for distance.  (And I guess some cataract surgeons just assume that everyone would prefer this.)  This vision is preferable for participating in many sports, reading road signs while driving, enjoying spectator sports and movies, as well as many other daily and social activities.  If someone's post-surgery vision were set to 20/20 for distance, they'd need bifocals for intermediate and near vision post-surgery.

[K-D]

Thanks much for your explanation.  I feel a lot better.

[Occupant]

Hi,
I wish someone could explain to me the Depth of Field I am going to realize with monofocal lenses. Let's say they are set for distance @ 100Ft. Does that mean every thing will be in focus from 99-101FT, 50-150Ft, 20-180Ft or what? I haven't made a decision yet, because the doctor tells me, there is still a chance that a Restor lens for -9.0D would be available by spring of 2007. So should I wait or forget about it and go for monofocals?

[JodieJ]

It's my impression that setting distance vision to 20/20 would include everything from a few feet away to infinity.  I think that the ReZoom multifocal currently comes in your power.  An alternative would be monovision with monofocal IOLs.

[Ag-i-doc]

everything over 20 feet or so is considered "optical infinity".  a person cannot "focus" for the difference between 50 ft and 100 ft.  or 20 ft to 50 ft for that matter.  there is no "focus" difference in the human eye past 20 ft or so.