Contact lenses and diving -Questions Welcome - by Idocsteve

[JKPAO]

idocsteve, I am new to contacts and I am currently trying soft lenses. One month duration type.

Is there an inside and an outside to this type of lense? They seem to cereal bowl both ways.

Is it resonable for the doctor to be off a little with one eye (initial) script?

Thanks!
See you topside! John Clearley I hope!

 

[JonKranhouse]

Hi JKPAO,

RE your 1-month duration contacts, I leave it to Steve to answer your questions (inside/outside, accuracy of Rx). But here's some advice about using your contacts for diving (you might consider one-day disposables on dive days to eliminate cleaning hassles, then switch back to your 1-month lenses for day-to-day)...

Do not sleep in contacts after diving or swimming!

From our website:

• 75 million people worldwide wear contact lenses... for many good reasons.

• Maximum resolution: Most people needing vision correction achieve higher low-contrast acuity through contact lenses than through eyeglasses or LASIK.

• We only recommend soft contacts for diving; among other reasons, they have a larger diameter which makes it almost impossible for a lens to fall out when you squint if water splashes in your face (Research by SPUMS glued sutures to contacts and tried tugging contacts out while submerged)

• Swimming with contact lenses does not raise the risk of eye infections. But keeping contacts in for many hours -- or days -- after swimming IS VERY RISKY. Timely removal of contacts virtually eliminates the risks of infection because your eyes' natural tears flush away bacteria commonly found in water. (e.g. Pseudomonas Aeruginosa or Acanthamoeba).

Fresh water (e.g. lakes, swimming pools and hot-tubs) often carries more infectious agents vs. salt water at typical dive destinations .

• Fit to dive = fit to use contacts; don't wear contacts if:

1. You have an impaired immune system (e.g. fever).
2. You have an existing eye infection or corneal damage.
​

• Rinse your eyes with sterile saline solution before putting contacts in -- and before removal to prevent the lens from "sticking" to your cornea (caused by an osmotic imbalance). Of course wash your hands before handling contacts - hand sanitizer works well - just rinse alcohol off with saline).

• Daily disposable contacts are the most convenient for hygiene compliance. If using weekly or monthly disposables, be sure to disinfect per your eye doctor's instructions - and DO NOT reuse cleaning solution!

 

[JonKranhouse]

Corneal edema caused by diving with hard contact lenses has been a known problem for many years: a 1979 UHMS article. Rubicon Research Repository: Item 123456789/4859

To reduce corneal edema, “fenestrations” (Latin for “windows&#8221, actually tiny holes drilled through rigid contact lenses, have been used for decades. Here are abstracts from 1977 and 1981 paper about “newer” methods of fenestrating lenses.

But fenestrations have had mixed results: (1980 JAMA article RE hard contacts and diving)
JAMA -- Abstract: Adverse Effects of Contact Lens Wear During Decompression, September 12, 1980, Simon and Bradley 244 (11): 1213

So for this and many other reasons, SOFT contacts are far superior for diving, particular daily disposables if available for your Rx - to virtually eliminate any risk of infection if you get lazy and don’t follow hygienic lens-handling rules.

If you wear RGP because of a high CYL (astigmatism), and you think soft contacts are not available for your Rx - maybe you should switch to an Rx mask. That said, there are literally hundreds of variations of soft contact lenses with toric correction. Ask your eye doc to do more research.
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Quick hijack for an IMPORTANT TOPIC

Lots of diving medical “experts” don’t appreciate basic concepts of ophthalmic health. Proof? A group of diving MDs had their Fijian holiday ruined by plunking their masks into a shared rinse tank between dives -- which spread conjunctivitis among the group! Why / who / how did this practice of commingling dive masks ever start?!
Rubicon Research Repository: Item 123456789/5184

When gaps in knowledge from “learned intermediaries” create risks to the health and life of recreational divers - THANK GOD for ScubaBoard to communicate about those gaps - and to fill those gaps. And THANK YOU Steve for doing your part. But God won’t handle the Board’s legal defense. If we want to defend our right to spread knowledge about keeping safe while diving, it’s up to us. Please donate today!

Hijack over ; - )
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OK - for the über-technoids following this thread…
Experimental fenestrations have been tried in soft lenses, to increase tear-flow, but these are not on the market AFAIK. Fenestrations Enhance Tear Mixing under Silicone-Hydrogel Contact Lenses -- Miller et al. 44 (1): 60 -- Investigative Ophthalmology & Visual Science
One research project found fenestrated soft lenses to be less comfortable vs. soft lenses with no holes: Comfort of fenestrated hydrogel lenses | QUT ePrints

 

[JonKranhouse]

Orthokeratology -- commonly called "Ortho-K" is a non-surgical alternative to LASIK - arguably safer with fewer side effects, particularly if you have naturally dry eyes.

Fenestrations are used on specialized “Orthokeratology” contacts that reshape your corneas while you sleep.
(now aren't you glad you learned all that stuff about fenestrations?)

Orthokeratology is efficacious, well-proven and for some may be the best solution. But orthokeratology is not permanent - if you stop wearing the contacts at night (some only have to wear a few nights per-week) your corneas will return, in time, to close to their original geometry. Some noted cinematographers who’ve won Oscars chose this solution, because there’s vastly less risk of reducing acuity. “20/20” is misleading because it’s measured with high contrast black-on-white characters. The real world is gray-on-gray, which requires superior acuity to see accurately.

Arguably, it is fraudulent to misrepresent LASIK results as "better than 20/20" without explaining research that finds low-contrast acuity is reduced post-LASIK. Everybody has their own metric for "good enough," but everybody deserves to make their decisions without facts being withheld or obfuscated just to induce commerce.

Two good articles RE “Ortho-K” Wikipedia & All About Vision.

 

[idocsteve]

Is there an inside and an outside to this type of lense? They seem to cereal bowl both ways.

Every soft contact lens has a "right" way and and an "inverted" way, although some may look about the same regardless of whether they're flipped, and they might not feel any differently, however, they will not fit properly if they're inside out, and because the edges will be slightly curled upwards, the fit will tend to be looser and there will be more interaction with the eyelids, especially the upper lid.

You need to practice determining which way is the correct way and which is the inverted position. Do this by placing the lens on your finger, but keep that finger as dry as possible so only a bit of the "bowl" of the lens is in contact with the finger, so it's not too flat. Examine the edge of the lens closely as you sort of turn your finger, allowing you to see around the edge. Flip the lens the other way, and repeat.

It should soon be obvious to you which way is more of a bowl and which way has an outward curved edge, more like a saucer; the latter is inverted. Another way is to place the bowl of the lens in the crease formed in your palm when you go from an open to closed fist, the lens should close like a clam if it's correct, it may flip backwards or just not close properly if it's flipped.

Practice with those two techniques, and if you still can't tell by look or feel, then I guess you can just sort of roll with it and see how it goes. I've had patients tell me that they never bother checking, and they wear the lenses however they go into the eyes and they never seem to have a problem.

Is it resonable for the doctor to be off a little with one eye (initial) script?

Some doctors are more accurate with refractions than others, some doctors don't communicate well with their patients and mistakes are made, some patients either misunderstand, get confused, guess at "which is better, one or two", or just can't tell the difference between "lens flips". Sometimes the eye doctor won't prescribe the full Rx because it's a significant change from the first one, sometimes lenses are made out of tolerance...lots of reasons why it might not be right the first time, so yes it's reasonable to be "off a little bit with the initial script".

How the doctor responds when you return with complaints of blurred vision tells you a lot about him or her. If they try to blow it off and tell you "everything's fine" when you know it isn't, and without a clear explanation as to why you "think" there's a problem when they are certain there isn't a problem, well then there's a problem, and it's not with the glasses.

When prescribing contact lenses there's a lot more variability and more of a chance that an Rx may need to be changed or fine tuned, which is why I require a 1 week followup before ordering a supply of contact lenses for the patient.

 

[beachnik]

Since we are talking about monovision I normally wear -3.00 contacts in both eyes and have been using the Diveoptix stick on lens in my mask. Going with only one contact causes a little too much difference so I have been thinking about splitting the difference by using one -3.0 and one -1.50 or -1.75. Any suggestions.

I have the same correction that you have (-3.00 for distance - both eyes) and presbyopia. I've been using -3.00 for the dominant eye and -1.50 for the non-dominant eye. Works nicely for me.

 

[Pearldiver07]

Steve,

In a couple of posts quite a bit back you mentioned hybrid lenses (RGP center with soft skirt) for keratonic patients, but had no personal history. I have significant keratoconus, and am post-surgical in one eye.

I wear them (Synergeyes brand) and they work great. For everyone else: they give the excellent clarity of a RGP with the comfort of a soft lens. I use mono-vision fittings (correct term?? - one for near sightedness, one for reading) and this set up works great.

Only down side? If you lose one of these, it's really going to be painful. They're quite a bit to buy (figure around $800 or so with fitting/follow up if you've got Keratoconus, from my experience). Of course, one of the upsides to having keratoconus is that my lenses (and post-surgical lasik) are covered by my insurance company. I only pay deductables.

 

[Aggiebq86]

My glasses currently have some prism included in the scrip. Are there exercises that can be done to eliminate this requirement? I'm interested in either surgery or soft contacts but have been told these aren't an option due to the prism requirement. Any suggestions?

 

[idocsteve]

My glasses currently have some prism included in the scrip. Are there exercises that can be done to eliminate this requirement? I'm interested in either surgery or soft contacts but have been told these aren't an option due to the prism requirement. Any suggestions?

Thanks for your post, this is a bit of a different topic than most on this thread...

The exercises to which you refer are often referred to as "Vision Therapy". It's a controversial topic among eye doctors, in general optometrists such as myself recognize their usefulness, while many ophthalmologists (eye surgeons) tend to "poo poo" them... although acceptance of Vision Therapy has increased. Many ophthalmologists now work closely with optometrists and do VT in their offices, and VT is usually accepted by most major insurance companies- which means a lot in terms of it's perceived effectiveness.

That much said, Vision Therapy is more favorable for some eye conditions. If you have a vertical muscle imbalance, then the odds are not good. If your eyes are turned inward, and your prism is BO (Base Out), the prognosis is also not as good (but not necessarily hopeless). If the prism is BI (Base In) to correct a tendency for one eye (or both eyes alternately) to turn outward, this is the most favorable case for Vision Therapy, assuming the eye turn is 1) intermittant not constant 2) not longstanding and 3) not due to either an accident or medical condition such as a nerve palsy secondary to diabetes for example and 4) when the eye turns outward you get double vision (when not wearing your glasses).

Contact lenses are probably not an option for you because without the prism that you presently wear in the eyeglass lenses, you would most likely see double or experience severe eyestrain and/or headaches, and contact lenses cannot be made with prism.

Surgery- to correct the eye muscle imbalance- not refractive surgery to eliminate glasses, may be an option for you.

 

[Lindzi258]

I wear mine I also invested in a prescription mask as a back up!