Farsighted lens question

[Painter]

I have a new Tusa CEOS mask that I bought because it is possible to order prescription lenses in positive diopters for it without having them custom made. The downside (for me) is that my prescription is OD +3.5 OS +3.25 and the Tusa lenses are only available for my OS in either +3.0 or +3.5. So should I get the OS as +3.0 or +3.5. I suspect it won't make much difference one way or the other, but I wonder if anybody has an opinion?

 

[arew+4]

As a fellow farsighted person, I would go with the slight under correction as I think the water RI acts like plus .25 or something. I don't know if dive lens compensate for that.

 

[Etmutt]

As a fellow farsighted person, I would go with the slight under correction as I think the water RI acts like plus .25 or something. I don't know if dive lens compensate for that.

100%, go with the lower one.

 

[John C. Ratliff]

My feeling is that you should do neither, but rather invest in the SeawiscopeEY.

Seawiscope: Scuba divers' near vision aids and other small items

SeawiscopeEY is a near vision aid for divers who have difficulties to read dive computers, check out, examine small creatures and frame them within underwater LCD camera monitor. It is not a gauge reader, but much more and better.

scuba-vision.com

I have been using this device for about ten years now, and it is wonderful underwater. When not needed, you can pull it up over the mask. Underwater, these corrected lenses allow full very close vision of very small things (I watched a hydra on a leaf feeding in the Clackamas River a while back). This new vision tool was developed by a college instructor in opthamology in Hong Kong for us older divers with the need for correction, but without having to change the lens in a mask.

SeaRat

 

[Painter]

My feeling is that you should do neither, but rather invest in the SeawiscopeEY.

Seawiscope: Scuba divers' near vision aids and other small items

SeawiscopeEY is a near vision aid for divers who have difficulties to read dive computers, check out, examine small creatures and frame them within underwater LCD camera monitor. It is not a gauge reader, but much more and better.

scuba-vision.com

I have been using this device for about ten years now, and it is wonderful underwater. When not needed, you can pull it up over the mask. Underwater, these corrected lenses allow full very close vision of very small things (I watched a hydra on a leaf feeding in the Clackamas River a while back). This new vision tool was developed by a college instructor in opthamology in Hong Kong for us older divers with the need for correction, but without having to change the lens in a mask.

SeaRat

Thanks, but no, I need corrective lenses.

 

[BoatingDave]

100%, go with the lower one.

Agreed. I actually have bifocals in my mask. -3.5 for distance and +2.5 as “readers” on the bottom. Made a HUGE difference for me now that I can easily read my gauges.

 

[CanadaDan]

I know you didn't ask for mask options... but...

For an equivalent fit (I used to dive a Ceos for the great fit) and WAY better lenses give SeaVision USA's Ultra 2200 mask a try. I was reluctant to give up my Ceos for the fit but the Ultra 2200 was a great swap for me. They will make the lenses to your exact numbers with no compromise.

SeaVision USA | Prescription Dive Masks

SeaVision Prescription Dive Masks and Swim Goggles for scuba diving, snorkeling, swimming in the pool, or any underwater activity. Each order custom made.

www.seavisionusa.com

 

[deeper thoughts]

My feeling is that you should do neither, but rather invest in the SeawiscopeEY.

Seawiscope: Scuba divers' near vision aids and other small items

SeawiscopeEY is a near vision aid for divers who have difficulties to read dive computers, check out, examine small creatures and frame them within underwater LCD camera monitor. It is not a gauge reader, but much more and better.

scuba-vision.com

I have been using this device for about ten years now, and it is wonderful underwater. When not needed, you can pull it up over the mask. Underwater, these corrected lenses allow full very close vision of very small things (I watched a hydra on a leaf feeding in the Clackamas River a while back). This new vision tool was developed by a college instructor in opthamology in Hong Kong for us older divers with the need for correction, but without having to change the lens in a mask.

SeaRat

Very interesting and it seems you only have to clip them to your mask

 

[tursiops]

There may be some confusion in this thread. A far-sighted person (can only see things far away, not close) needs plus diopters for vision correction. A near-sighted person needs minus diopter. The air-water lens in the mask also acts as a bit of a lens, with a strength of maybe -0.5 diopter. So if a near-sighted person needs a correction of (say) -3.0, they might be quite happy with mask lenses of -2.5. On the other hand, if they are farsighted and need (say) +4.0, then they might want to get +4.5 to compensate for the mask.
However, many folks like to choose their correction so they can see little things up close. The nearsighted folks just under-correct, because their uncorrected vision is already good fir small and near. Farsighted folks have to over-correct, so the +4.0 fellow in the example above mat need to bump it up a bit.

Finally, there is the issue that you don't really need distance vision underwater...

THESE are all the reasons why you go to an outfit like PrescriptionDiveMasks.com and tell them your desires and constraints. They do their job well.

 

[John C. Ratliff]

Very interesting and it seems you only have to clip them to your mask

That is correct, they clip onto your mask. They now have two means of doing this.

So far as people saying farsighted people actually need a prescription mask, I've found that not true. With a prescription mask, I have problems navigating the first steps out of the water, as the down-vision is affected by the prescription/close-up lens built into the mask lens. I don't take my mask off until I'm out of the river. My prescription mask interferred with foot placement on slippery rocks as I exited.

In contrast, with the SeawiscopeEY, I was able to simply flip it up and out of the way when exiting. There was no interference with my down-vision. You can see the SeawiscopeEY in use in this video of "Getting the Lead Out," whereby I took a bunch of fishing weights out of the Clackamas River.


SeaRat