What are Hard Contact Lenses?

Ever wondered, what are hard contact lenses? Or what is the difference between hard contact lenses vs soft?

In this video, watch as Damon Ezekiel talks about Hard Contact Lenses, also known as RGP contact lenses.

You’ll learn more about: 

  • Why wear Hard Contact Lenses?
  • How are they better than Soft Contact Lenses?
  • How long do Hard Contact Lenses last?

Watch this video to find out more (approx 15 mins): 

Here’s the full text from the video above: 

(Leigh)- Welcome everyone. I’m here with contact lens specialist and owner of Ezekiel Eyes, Damon Ezekiel. Welcome Damon!

(Damon) Thank you, thank you for the invite.

(Leigh) In this video we’re covering what are hard contact lenses, and to give you more of a picture of more of an understanding of what they are. So Damon, what are hard contact lenses?

– Thanks Leigh, so you know in the contact lens world, there’s soft lenses, which I think the majority of the world know about, and then there’s rigid lenses.

And I prefer to talk about hard lenses and call them rigid lenses.

‘Cause hard lenses, patients get a sense that this is something that’s not as comfortable.

So you know we prefer to deal with the talk about a rigid contact lens. A rigid lens is rigid material that doesn’t flex. And we need a rigid contact lens for certain patients, because of the shape of their eye.

It really gets down to the shape on the front of their eye. And if it’s distorted or irregular, that is exactly what the patient needs.

There’s many different types of rigid contact lenses. There’s different materials, the majority the materials we use, we really narrowed it down to one or two because they’re nice and stable and they are a high breathing material.

Most of my contact lens complications I get is with soft lenses. So rigid lenses are easy to clean, keep clean. They breathe more than the soft lenses, and they’re just so much healthier.

You take a little bit longer to get used to it than a soft lens. But most of my rigid contact lens patients love them and their vision is sensational. So the quality of their vision cannot compare to what you get with a soft lens.

(Leigh) – Okay.

(Damon)  When a patient comes in, we will talk to them about what you need. And if it is a rigid lens, we’ll talk to them about the different options. We start at the basics, and then the different options from there.

(Leigh) – What is it about rigids that’s easy to keep them clean?

(Damon)- Because it’s a rigid lens it’s literally firm. You can actually put a little bit more pressure on and clean them and rub them.

Whereas soft lenses, it’s a lot harder to get a physical rub onto them with any punch to it.

– Yeah.

(Damon) – Being soft lenses so much more porous and absorb more bacteria, protein, calcium from your tears and things like that, whereas a rigid lens, even though it breathes, it’s a lot harder to get a build up on the lens. It does happen.

But if you can keep it clean, and you know it’s just some, it is an easier lens to keep clean for longer.

(Leigh) – That’s great. And what’s the typical lifespan for a rigid lens?

(Damon)- So the majority of our patients would get two years out of their contact lens. So if you look after them well, you get the two years.

– Right.

(Damon) – Okay. And we recommend two years, ’cause as you get closer to two years, well as lenses get older, through wear and tear they will warp and change shape so they’re no longer a size 10 shoe, they’ve now moved up to 11 and a half, and the pores in the lens will block up so they will breathe less. So we do like to replace every couple of years.

– Sure. What do rigid lenses look like, say a corneal lens?

(Damon) -If we look at a soft lens has a diameter of say 14.3 millimetres, a rigid lens is anything from say, 8.6 millimetres up to 11 millimetres.

So a soft lens will cover across the coloured part of their eye onto the onto the white, whereas a rigid lens is just gonna sit within the coloured part so it’s a lot smaller. And all contact lenses, when a patient blinks, the lens should move, and we have this tear pump that pumps tears out, and pulls new ones underneath. So, we need to make sure that the lenses move. But it is definitely smaller and we fit them a lot differently to soft lenses.

(Leigh) – And just like a shoe, we want it to move a little bit but not too much.

(Damon)- That’s right. Yes. So, you can go to the extremes where it’s moving too much, or the other side where it’s too tight. And a tight lens feels fantastic because it doesn’t move. But over time, it will cut down the amount of oxygen to the eye.

And we’ll get more blood vessels and it’s gonna cause a lot of complications.

So there’s that fine line between the lenses moving too much, not enough, to just perfect.

– Sure. What are rigid contact lenses used for?

– The majority of rigid contact lenses are fitted for patients with a distortion on the front of their eye or very high prescriptions.

But a lot of it gets down to that curve on the front of the eye.

So when a patient comes in, one of the, early on, one of the things we do is to measure, we take it topography map on the front of the eye. So it shows me the whole curve, and shows the valleys and peaks and troughs so then we can work out, where there’s an irregularity down the bottom or off to the side, and that’s where if you’ve got an irregular shape to the eye, what we want to do is put a new front to the eye, and that’s where a rigid lens works beautifully.

Whereas a soft lens is just gonna wrap on, so that distortion is still there. So unfortunately patients, and we see a lot of patients with distorted corneas, the front of their eyes, distorted, a soft lens and glasses it’s just can’t get them to the vision that they need. So a rigid lens will just improve the quality of their life amazingly.

(Leigh) – For sure. And even if I don’t have a distorted cornea, if I did have some astigmatism, it’s likely that a rigid lens would give me sharper vision?

(Damon)- Yes and no. Same again when we measure the curvature on your cornea. It depends where that astigmatism is. If it isn’t on the front of the eye, on the cornea, on the front, or is it within the eye. So it does depend.

But the important thing is I see a lot of patients come in and say I’ve been elsewhere, I have an astigmatism and I’ve been told I can’t wear contact lenses. Depending on what that astigmatism is and where it is on the eye, within the eye, 99% of patients with an astigmatism can wear contact lenses.

– That’s amazing to me. To be told that finally they can.

(Damon)-  And if you’re driven and you want contact lenses, then we can certainly look after you.

– That’s really good. Are rigid contact lenses better for dry eyes?

– Dry eyes is a tough gig. There are certain conditions where we do fit patients with rigid lenses in the dry eye world. And we’re not talking the little corneal lenses. What we tend to do is we use what’s called a mini scleral and a mini scleral is a lens that’s anywhere from say 14 millimetres to say 18 millimetres. So it’s big and it sits on the white of the eye.

The beautiful thing about these lenses is that they sit on the white and they vault up over the coloured. So the white of the eye, the insensitive, and there’s this beautiful big T-line between the back of the lens and the front of the eye. So there’s this is beautiful wet bed.

Then we keep the front of the contact lens nice and wet and moist. And for certain dry eye patients, you know, it is fantastic. There’s a lot of things we would try and do beforehand but it’s certainly an option. But, that’s one of the things we do at Ezekiel Eyes is try and really customise what you need and let’s try these. Okay, that didn’t work. Well let’s try this. We have a very big armoury of goodies to play with whether it’s for dry eyes or soft contact lenses or rigid contact lenses.

– Absolutely. And you’ve got the drive, the experience to be able to know what’s the best suitable lens for each person.

– Absolutely. And you know Leigh, we have patients who come in who are wearing the little rigid lenses and it might just be 12 months old and they need a little bit of a polish. So in our practise we’re very spoiled. We have a polish, a little polishing system at the back of the house. We’ll take the lenses off the patient, go round the back while the patient’s in the chair. We can polish the lenses, adjust the edge, increase the edge so it’s not, so it’s more comfortable or give them a clean, a little bit of a polish. 40 minutes later they clean up back into the patient, no downtime for the patient. So in that aspect it’s fantastic that we can do in-house adjustments, no downtime for patients, so we’re very spoiled, but that’s what we do for our patients. We want to go that little extra step.

– That’s great. You go the extra mile to keep people happy.

– Absolutely, absolutely. And do as much as, we like to do as much as we can in-house.

– Absolutely. So how easy are rigid lenses to put in?

– So Leigh, when we first see our patient, and we diagnose and we’ve done our trial fitting, the patient will come back a week or so later, and then we’ll fit the lenses, check that they can see.

That the fit of the lens is looking okay, and if they’re looking as it should be, we’ll then teach the patient how to get them in and out and clean them and look after them.

Now in our practise we will not let a patient take the lens home unless they’re comfortable and they’re confident that they can get them in and out. And that’s fine. Some patients will come back three or four times. But from my point of view, If a patient takes the lenses home, and they can’t get them in and out, they’re gonna sit in the top drawer, and that’s it, nothing’s gonna happen.

So it’s really important that we sit down and make sure they’re comfortable, and you need to be comfortable.

So sitting down over a white towel, and we teach them the in and the out and how to centre them. All the pitfalls, run through the solutions, all written down in a booklet, so that when they leave, it’s all there. We give them a wearing schedule, so it’s a couple of hours today, tomorrow, and build up that schedule. And like I said if they’re not comfortable, great, leave me the lenses. Come back a couple days later and we’ll just keep going through it. It’s like anything new.

When you tie a tie, your shoelaces, you’re gonna get comfortable with touching your eyes and touching these little bits of breathing plastic. So once they know and they’re shown, it is easy, but it’s a learning curve. The first week, you know, it might take a little bit of time, but by the time I see them for review in a week or 10 days, most of my patients are very happy, they’re in and they’re out.

At our review consultation we always talk about how is the in and the out, and solutions, and we try and explore all those little holes where they’re just not sure. And some patients do come back a second time and say, look, I just can’t get this one in, or one out, and we sit down and just run through it again. So as long as the patient’s comfortable and confident, then I’ll let them take them home.

– Yeah, because it matters to you that you know how they’re doing, how well they’re doing with their lenses.

– Yeah, otherwise they’re not gonna wear them, then it’s, I’ve failed. And I haven’t got the patient to where they need to be.

– Yeah.

– And there’s different techniques to get them in and get them out. And that really depends from patient to patient. So that’s a part of what we do is tailor make. For you what you need. If one type of removal technique is not working for you, Well great. Let’s try a different option. And there’s a couple of, there’s probably three different ways you can get rigid lenses out. It’s just a matter of let’s start with what I think is the easiest, which works for 80%. And if you, if it doesn’t work for you because of the anatomy of your eyelids, then all right then, fine, let’s try something else.

– At the end of the day, you will be able to practise, and you’ll get a technique that works best for you.

– Absolutely, yeah. But the important thing is that you know that you’re confident, that when you leave my room, you’ll be able to do it at home by yourself.

– Yeah, absolutely. So I’ve got a rigid lens in my eyes. Can it get lost behind the eye?

– Well that’s a great question. So one of those things we do when we’re teaching patients how to get lenses, when they have their second visit, is a centring technique, that the lens, which should be sitting on the coloured, slides down, up, down, left, right. How do we get it back on?

So remembering with a rigid lens because it’s got this curve to fit on the coloured, if it slides onto the white it’s gonna stay there. It’s not gonna come back. So the white of their eye makes an envelope with the inside of their lid.

So if you look right up, it’s about there, it’s not that far. And right down, it’s there. So we teach patients a centering technique, so if the lens is up, we get them to look down, and we just with a little bit of pressure pull the lens down, holding it through your top lid, look up towards where your finger is, which is holding the lens on the inside through the lid. And it will just slide back on.

So it’s very simple, in the corner, up, down, and same again. The majority of time, obviously, if you can put the lens straight on the coloured, straight off the coloured, then you don’t have to, you know, chase it around your eye. But but it’s not gonna get lost, and oh, here it is. It can only go up and down so far, so.

– Awesome. that’s good. Could you tell me if I’m interested in looking at rigid contact lenses, what sort of ballpark am I looking at for a cost.

– So there’s a huge variety of lenses, so, off the top my head, I think the rigid one starts at 395 each. And then depending on whether you’re having two curves on the back and two curves on the front, the cost increases.

If you’ve got keratoconus, or you’ve had post surgery, that changes, and then we go to mini-sclerals, and they’re over $1,000 each. And then we go to a bigger scleral which is, so a mini scleral is up to 18 millimetres in diameter.

We can also fit these, rarely, but we do fit these scleral lenses, which are actually fenestrated, so they’ve actually got three holes in them, and they’re up to 24 millimetres. So they’re big, that sit right in, and they’re over $2,000 each.

So, they’re all, it really depends on what you need. We always try and start at the most basic, and if we can get you a great result, comfort and vision and you’re happy, you can wear it all day, great. If not, then we’ll look at tailor-making something, and upgrading you to something.

– Thanks for talking to us about this.

– Thanks, well, thanks for your time. I really appreciate it.

– That’s great. If you’d like to make an appointment with Damon, what’s the best way to make an appointment with you?

– So, the best thing to do is ring 08 9386 3620. You can go to our website. My colleague and myself are ready whenever you are, or at the bottom of this video, there will be some, some links.

– Fantastic.

– Thank you.

– That’s great. If you liked this video, please click like, and also share it with a friend as well. Thanks very much for watching.

 

Rigid gas permeable contact lenses

Rigid Gas Permeable Contact Lenses (RGP) are lenses that don’t flex.

They are made from plastic polymers that allow oxygen to flow to the eye.

At Ezekiel Eyes we specialise in all types of rgp or rigid contact lenses. We fit these lenses for people just like you everyday!

Why Rigid Gas Permeable Lenses? They are especially beneficia if you have:

  • Astigmatisms
  • Dry Eyes
  • Keratoconus
  • Post-Graft
  • Post Laser Surgery (eg. PRK)
  • Traumatised Corneaes
  • Or if you have lots of deposits on your soft contact lenses,

Rigid Gas Permeable are easier to clean than soft contact lenses and better deposit resistant.

 

Learn more about the material that we like to make your rgp contact lenses out of:  

What is the Boston XO contact lens material?
Boston XO is the brand name of the material we at Ezekiel Eyes utilise for the majority of our rigid gas permeable contact lenses, including lenses for keratoconus, orthokeratology and post surgical contact lenses.

Boston XO (BXO) is our material of choice due to its excellent material properties. The official material name is Hexafocon A.

What is Oxygen Permeability?
BXO has an oxygen permeability index of 100, one of the highest in the Boston family of materials.  This means a higher percentage of oxygen passing through the lens and reaching the cornea to maintain good corneal health.
What is Wettability
Wettability is a measure of the area covered by a drop of liquid on the lens surface.  This is closely related to the surface tension forces of the contact lens surface.  The more wettable the contact lens material, the more area the drop of liquid will spread.  It is very difficult to develop a testing standard that accurately predicts the on-eye wetting performances as tear film components vary significantly from person to person. However, in a laboratory setting, the BXO material was able to outperform the older gas permeable materials.
Durability (Hardness, Modulus, Toughness)
The durability of the contact lens is dependent on the combination of hardness, modulus and toughness of the contact lens material.

Hardness (index of 112) refers to the resistance of a material to indentation.  This ensures that the surface of the contact lens is free from any depression on the surface which may affect the long term comfort of the contact lens.  One every day example of this property is dropping the rigid gas permeable contact lens on a hard surface without causing any dents on the contact lens surface.

Modulus refers to the amount of force applied to a contact lens material to deform (or cause strain within the lens) until breakage occurs or until the deformation reaches some predetermined point. BXO has a modulus index of 1500MPa.  This index ensures that the force applied to the contact lens, from the front of the eyes, does not change the original shape of the contact lens.  Any deviation from the original lens curvature will affect the visual outcome.

Lastly toughness (2.6MN/m3) refers to the amount of energy a contract lens can absorb before the material is broken or flexed to some predetermined deformation point.  This quality is closely related to contact lens handling and cleaning, as the force of handling and cleaning motion may cause excessive strain or flexure on the contact lens.

Does it include a UV Absorber?
Ultraviolet (UV) radiation absorber in the contact lens reduces the amount of UV reaching the underlying structure of the eye, but does not offer total protection.  Protective eyewear (such as sunglasses) is still recommended for maximum protection.
What is a Plasma Treatment?
This advance treatment on the contact lens increases the wetting surface of the contact lens, which may improve the comfort of the wearer.

The BXO material offers super-permeability and is as dimensionally stable as older generation gas permeable contact lenses of much lower oxygen permeability.

What Solutions should I use with RGP contact lenses?
The surface of gas permeable contact lenses has unique properties such as an ionic charge on the surface and the increased energised surface due to the addition of silicon.  Therefore to maintain comfort and to prevent the surface from drying, the lens surface should be free from deposits.  The Boston range of solutions has been formulated to work with the unique surface properties of the Boston materials.
What is the Boston Advance Cleaner?
The Boston Advance Cleaner is specifically designed for newer materials like the BXO, which are more prone to lipid deposits.  This is due to the negatively-charged surfaces attracting the positively-charged lipid and protein components found in the tear film.  The Boston Advance Cleaner contains friction-enhancing agents to help mechanically break down the adhesion between the deposits and the lens surface without damaging the lens surface. The ‘soap-like’ (surfactant) property of the solution then envelops the lifted deposits which prevent the deposits from rebinding onto the lens surface.
Boston Advance Comfort Formula Conditioning Solution
The Boston Advance Comfort Formula Conditioning Solution provides disinfection and improves wettability for the BXO material.  Water attracting polymers in the solution are attracted to the contact lens surface which makes the lens surface more ‘moist’.  This allows the lens to wet better and stay wetter longer in between blinks.  This, in turn, decreases lens surface drying and help repel deposits until the tear film coats the lens to maintain lens wetting.  The solution also contains disinfecting agents, which are effective is destroying harmful microorganism on the lens surface.
Boston One Step Liquid Enzymatic Cleaner
The Boston One Step Liquid Enzymatic Cleaner is used once a week to remove stubborn deposits and improve contact lens wearing comfort.  The enzymatic cleaner works together with the disinfecting step.  Maintaining lens cleanliness helps maximises the contact lens life and also to maintain wearing comfort.
When do I use Boston Rewetting Drops?
Over time, as a result of environmental factors, deposit formation or inadequate blinking, the smooth layer to tears attracted to the lens surface will gradually break down.  When tear film continuity is not maintained the lens surface can dry out.  Protein and lipid deposits make use of these dry spots to attach themselves to the lens surface, causing discomfort and reduce wearing time.  The Boston Rewetting drops utilizes electrolytes that bind onto the dry lens surface to rewet the lens, prevent deposition and extend the contact lens wearing time.

At Ezekiel Eyes we pride ourselves on quality service and utilising quality products for our patients.  One of the contact lens suppliers we utilise is Geflex Laboratories.

Gelflex Laboratories is accredited with:

–       ISO 13485:2003 – Medical Devices Quality Management System.

–       Annex V of MDD 93/42/EEC (CE mark for Europe)

–       ISO 14971:2007 – Medical Devices – Application of Risk Management to Medical Devices.

–       Therapeutic Goods Act 1989 – The Manufacturing Principles

–       Therapeutic Goods (Medical Devices) Regulations 2002 – Product Quality Assurance

–       Conditions specified in Certificates AU Q00130/01 and MR Q00050/01

–       A registered foreign manufacturer of contact lenses with US FDA