Underwater Vision Question - Near/Far sighted

[tuffshed]

I've been wondering this for a bit and haven't been able to find an answer anywhere so I thought I'd ask here.

After just recently becoming an old fart, my vision isn't what it used to be. I now wear reading glasses to see things that are close up. I've heard many times that objects appear 33% closer underwater. So I'm wondering if this will help/hurt my vision of objects close to me.

Consider this : If I normally can see things 3 feet and beyond without wearing reading glasses... If I am underwater (with my mask on) and there is an object 3 feet away, on land I should be able to see it clearly, but underwater it "appears" to be 33% closer or it appears to be at 2 feet away. Would I not be able to see it clearly as it appears to my eyes as though it is 2 feet away and my eyes cannot focus on something 2 feet away OR would I be able to see it as my eyes are focusing on something 3 feet away but it is just 33% bigger ?

This also begs the question, are people who are slightly near sighted at an advantage underwater, as oppossed to normal or far sighted people?

 

[Garrobo]

Can't answer all that technical stuff you are asking but I will tell you that having dived with a regular mask and then purchasing and diving with a prescription mask that I found out that I was missing a lot by looking through clear glass. I Googled 'prescription scuba mask' and found a company (Snorkel-Mart.com) which made up a mask for me. Cost was: mask $22.95, two prescription lenses $37, purge valve $3.50, extra strap $4.95 and S&H $7.75 for a total of $76.15. I'm satisfied.

 

[tuffshed]

Thanks, I actually have a bifocal style mask (SeaVision Guage Reader) which I will be using for the first time starting this weekend, but I was curious and here is why:

Since I have a bifocal style I will either be looking out the plain window or bifocal window. I obviously need the bifocal for close in viewing of small critters and my guages, and looking through the plain window will be all I need for far viewing (5+ feet) but I suspect that most viewing while scuba diving (for me anyway) is in the 2-5 foot area. I usually hover very close to the reef and scan for nifty stuff. I have what I consider to be excellent bouyancy so this has never been a problem. What I am wondering is if I will be spending most of my time looking through the bifocal area during my dives or if the magnifying effect of the water will help my age induced far sightedness.

I would think there are lots of divers in my age/vision category and while everyone teaches that things look bigger/closer, I'm really curious as to whether this will be helping/hurting and whether I need to take that into consideration if I need to get custom bifocals someday.

 

[stingray27]

I use those stick on magnifiers and they work great for me.