Cataract replacement lenses - one monofocal and one bifocal - is that a good idea?

I have one eye for reading and the other for distance and it works and no glasses. But not perfect yet. Doctor said i may need a touch up in a month.

I have a monofocal lens in my left eye for reading and a Symfony Toric lens set for distance (which also gives me good Intermediate distance vision). Thus, I am very happy with the ability to see at all distances during the day, after having LASIK enhancment to remove astigmatism and for minor prescription correction.  I do have some night vision issue due to seeing multiple concentric circles around lights at night, as discussed in my blog, "'Has Any One Else Noticed this Unusual Vision Issue with Symfony Lens'.

However, your surgeon probably made the right decision to not implant a monofocal lens in combination with a bifocal lens. Typically, a bifocal lens is designed to provide good distance vision and good reading vision but not a good vision at intermediate distances. Thus, getting a monofocal lens in combination with a bifocal lens will provide you good vision only at large distances and at reading distance, but not at intermediate distances, which is exactly the type of vision as you are getting with 2 monofocal lenses. However, the night vision with the bifocal lens can be expected to be worse than with the monofocal lens combination.

At this point, you should really concentrate on getting the best vision without glasses at the distances of interest to you. If you can't see well at any distance, you probably have significant astigmatism, which needs to be corrected. If you can share your current glasses prescription and the two out of three distances; near, intermediate, or far;  at  which you would like to be able to see well without glasses, then we may be able to make a more specific recommendation to you.

Adding to my earlier post, I should add that by using 2 monofocal lenses instead of one bifocal lens together with one monofocal lens, your surgeon was not only able to provide you similar day vision and better night vision, but he / she also saved you about 2 to 3 thousand US dollars in lens replacement cost. So, you should be thankful to him / her for that.

I've seen posts from people on various sites with a premium lens in one eye who are happy with the results, as well as studies indicating the same thing. There are however a few options you can try before considering surgery, and a few surgical options to address your concerns.

Your concern over lack of near is the same as those with presbyopia who haven't had cataract surgery. If you are able to wear contact lenses (and many who tried then when young, but not recently, might be surprised at how much improved modern lenses are) then you can try multifocal contact lenses to get more near, or wearing one contact lens to provide monovision to give more near. Multifocal contacts have different optics and aren't going to be quite as high quality a result as a multifocal IOL, so if you don't like that you might still like a multifocal IOL, but they are much easier to just try.

They have daily disposables lenses that are likely the most comfortable, or extended wear lenses you can sleep in for a week or longer (depending on lens) and rarely need to worry about them. Unfortunately dry eye is an issue for some people with wearing contacts, but a temporary test at least might be useful, including monovision as I said. 

If you like monovision, they can do a laser correction, LASIK/PRK, or some variant of those, to focus one eye nearer in. There are also laser techniques that provide multifocal patterns, but I haven't had reason to research the quality of the results compared to other options.

There are corneal implants like the Kamra and Raindrop which were designed to provide more near vision for people with presbyopia, but they have also been tested for people with IOLs to provide more near. Since they are inserted near the surface of the eye, the surgery is lower risk than lens replacement surgery (even if lens replacement surgery is safe, there are risks in any surgery) and more easily reversible if you don't like the results. I don't know if they are officially supposed to do that in the US yet (I don't know where you are), since they are approved for presbyopia but I don't know if they are technically approved for use with an IOL (which shouldn't make a difference, but bureaucracts on power trips sometimes care about such things, though I don't know if they do in this case) or if surgeons just do it as an "off label use".

The Symfony option someone mentioned is what I have in both eyes which should provide more useable household vision, it provides better intermediate than multifocals (with a lower risk of visual artifacts),  though not as much really near, so it depends on your needs if that is the best option. ?There are bifocals with a range of adds (especially if you are outside the US, since there are fewer approved here) depending on what distance is most important to you. There are trifocals  (which aren't approved in the US yet, I don't know where you are) which don't provide as good intermediate as the Symfony, but almost as good, as well as providing better near, with slightly higher risk of visual artifacts than the Symfony.

 

One question is, do you need glasses for distance also,   do you have some residual refractive error, either being nearsighted or farsighted or having astigmatism? If so then laser enhancement might be required anyway for at least one eye, preferably with a contact lens trial beforehand for the result you want. 

One important questions is, why did your surgeon refuse to do  a bifocal in one eye? There are some surgeons that had bad experiences with early generation multifocals and haven't bothered to try the new ones (like people who tried the earliest smartphones or computers, vs. the far better current model ones). Others don't like ever dealing with patient complaints, and although the vast majority of patients with premium IOLs are happy, a minority do have issues (with only a minuscule fraction of them wishing a lens exchange).

 Did he say there was some concern in your case with having a multifocal lens,  such as perhaps having had laser surgery in the past and having an irregular cornea? Some surgeons too easily assume anyone who has had prior refractive surgery isn't a candidate for a multifocal lens, but fortunately others actually to tests to see if its a viable option since it is for many. They scan the cornea for instance to see how regular it is, since newer laser techniques may leave it in a reasonable state.  The Symfony is used in some cases where a multifocal isn't an option, or the Crystalens (which has some risk of complications the Symfony doesn't have,  so I didn't go for it, and a greater risk of needing readers, even if the visual acuity is technically comparable, perhaps because of the stress of the eye accommodating). 

 

Monofocals are used at different distances for each eye to simulate bifocal effect. It does mean near sight in one is blurred and distance is blurred in other..but this means you should see ok with use of both eyes. There is never any guarantee you wont need glasses as the final result is dependant on the health and shape of each eye. The point of a cataract op is to replace a cloudy lens with one you can see through. Whilst the surgeon is hopeful of also enabling correction of any visual impairment he cannot always achieve use of no glasses.