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prescription dive masks – how to choose between a bifocal or franklin split lens

Prescription Dive Masks – How to Choose Between a Bifocal or Franklin Split Lens

So, you’ve accepted that you might need some visual ‘help’ underwater. Your dive buddies appear to be dangerously further away with every dive. The views beneath the water are not so crystal clear as they used to be. And you have been struggling with the change between seeing underwater at a distance and then reading your gauges. A prescription dive mask is the way forward. And, now you have a decision to make as to which lenses would suit you best.

So, if you are looking for some help with how to choose between a bifocal or Franklin Split lens, then this blog will guide you through why bifocals add to the experience when diving; a little bit more about the standard bifocal and Franklin Split options; and how to take the next steps to prepare for your most visually awesome dives so far!

Why do we need bifocal lenses?

As if we don’t have enough to think about as we start to age, when we hit our 40’s, it’s sad but true that our eyesight gradually, but increasingly, loses focus on objects even close to us.

For diving this means our gauges, computers, and potentially the signs and signals from our dive buddies too. So, not only does it mean less than inspiring diving experiences as time goes on and might even start to become disheartening rather than the ultimate in underwater experiences we were used to. But it could also mean danger to ourselves and others if ignored for too long.

For many of our customers though, long distance vision is also a problem. So, for distance correction and in the case of Astigmatism, bifocals are often prescribed.

And the best news is that you don’t just get the best vision on land by using bifocals. We can also fit your exact prescription bifocal lenses to your dive mask too.

Why are bifocal lenses so effective?

Bifocal lenses are certainly not new. In fact, it was long believed to be Benjamin Franklin in the late 18th century who cut two pairs of lenses in half, and put them together, horizontally, so he could see objects close to him, whilst also retaining his distance vision, without having to carry both pairs of spectacles with him. Genius!

Over time, although we now know it might not have been Franklin himself who was the first to try it, the concept became known as the Franklin Split lens. The name has stuck, and it has become a firm favourite, for good reason!

When it comes to diving, we’ve explained in an earlier blog how everything you see through your mask is already magnified by around 33%. So, any minor visual impairments are rectified.

For more serious conditions such as double vision and astigmatism, and more severe short and long-distance sight problems a bifocal lens bonded inside your mask will create a whole new perspective for you. You don’t want to be using your usual glasses tucked inside your mask. And losing your contact lenses underwater is the last thing you want to be concerned about when all you want to do is safely enjoy the surroundings and overall experience.

If you’re skim reading this article (and I know we don’t all have the benefit of time to spare for lots of reading), take note here, as this next section really could help you with how to choose between a bifocal or Franklin Split lens!

What’s the difference between a bifocal and a Franklin Split lens?

If you’re just starting out and maybe a little unsure as to whether you can even handle bifocals underwater, because they do take some adjustment and getting used to even on dry land afterall, then a standard bifocal diving mask may well be the one for you. Although it comes down to personal preference and the width of underwater vision you are wanting.

The standard bifocal lens is based on your current distance prescription. Great for those of you who need some close up help for gauges, and distance vision correcting.

But it can be restrictive due to its size. Without going into the full technical detail, the reading lens is 28mm wide, although that doesn’t necessarily mean you will have visibility through that full segment. The width of vision you will have from that lens depends on the design of your mask. For instance, if your mask has a high angle from the nose piece, bifocals are not recommended, as the area you can read through is reduced.

You might want to consider going for something slightly more beneficial in the long run.

The Franklin Split lens is exactly that – two different lenses. The top is for distance and the bottom is for reading. And because both lenses are full width, this type of lens provides a much wider reading area than other standard bifocals.

Although the Franklin Split might not be perfect for all styles of spectacle frame, they are the ultimate bifocal diving mask.

Not just a favourite for regular expert divers looking for the best all-round diving experience (the Franklin Split is also known as the ‘Executive bifocal’ by the way), but it’s also one of the most popular with professional marine photographers and underwater cinematographers. And, trust me, those guys seriously need precise vision beneath the water to see every minuscule detail before they can even start to capture it on film!

Why a Franklin Split is your perfect prescription dive mask partner

If you are still on the fence over how to choose between a bifocal or Franklin Split lens, let me offer some final guidance as a fellow diver, and having been in the business of providing the highest quality UK manufactured prescription diving masks for many years, I see it from all angles (pardon the pun).

A Franklin Split lens gives you the widest possible or ‘edge to edge’ near vision, without compromising and distorting any of the quality or view. This, at the same time as correcting your distance vision too (the view even for those with double vision and astigmatism can also be improved).

But another huge bonus over the standard bifocal is that the Franklin Split is great for higher prescription requirements, as it can allow for more glass than would otherwise be possible with a thicker standard single bifocal lens.

How can I order my Franklin Split prescription dive mask?

Always happy to talk your dive plans or problems through with you before you make any final decisions, you will notice the genuine interest and enthusiasm we have for our customers here at Dive Sight.

With many years’ experience in this industry, we ensure you have not only the most appropriate mask for your diving now and in future, but we also manufacture your lenses according to your bespoke prescription. And if you already have your own tried and trusty mask, we will fit the lenses to that for you.

Check out our ordering process, which is simple and straightforward, whether for lenses alone (you send us your mask for the prescription Franklin Split lenses to be fitted), or to purchase one of our range of dive masks at the same time.

Your safety, comfort, and enjoyment whilst diving is what we are here to cater for, and what Dive Sight is all about. We can provide prescription dive mask solutions for all eyesight conditions, so nobody need miss out on the spectacle that is the underwater world!

We hope you have enjoyed reading how to choose between a bifocal or Franklin Split lens and look forward to hearing from you if you have any further queries or would like to comment on this or any of our other blog posts.


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