Friday, August 05, 2005

Plastic VS Polycarbonate VS Glass Lenses

In this segment I am going to talk about the different choices of material that lenses are available in.
This is another subject that was sparked by a previous comment on a prior post.
The subject was “ do I really need that, scratch resistant coating”.
In that post I stated that everyone needs scratch resistant coating because they do not clean their lenses properly so scratch resistant will help prolong the life of the lenses.
You can read that article if you like, by clicking the link in the archive section of this page.

To comment went like this:
If people just bought Glass lenses they wouldn't need to get scratch resistant coating's. It's amazing how the optical industry has brainwashed people into thinking that they need plastic lenses and then they tell them to get the lenses coated.

I have been in the optical industry for going on 17 years now,
and I am afraid I would have to somewhat agree with this statement.
That is exactly what happens, but that is also why in that post I threw in a shameless plug for my company, because I give free scratch resistant coating on every pair of lenses I sell, as opposed to most places that are pushing plastic lenses are also pushing the scratch resistant coating and charging for.

John Q. consumer has been brainwashed into thinking plastic lenses is what they need,
in fact, the deal now is everybody is pushing polycarbonate lenses,
on the premise that they are thinner, lighter, and impact resistant, which is all true,
but they are also more expensive than regular plastic lenses, of course, and just like plastic, or Glass for that matter, they're not for everybody.

So what I would like to do is discuss the pros and cons of all three of these choices.

Some of you along with myself included are old enough to remember back when we didn't have all these choices, there was a time when Glass lenses were the only thing you could get.
Then they came out with plastic lenses which everyone was excited about because they were much lighter weight, but what they discovered was they scratch easier.
The Glass lenses are a little tougher but they were so heavy.
And the mindset now days is people want their glasses to be as light weight and nonintrusive as possible, that is why they are pushing polycarbonate lenses now.

So,
Glass lenses weigh more and if you drop your glasses they may shatter because Glass is the least shatterproof.
But, Glass lenses give you the best optics, in other words you get better visual acuity through a Glass lens, and they do not scratch as easily as plastic or polycarbonate.



Plastic lenses are lighter weight, and much more shatterproof, but will scratch easier if you do not clean them properly, and you will lose a little visual acuity.
But this is still the most popular choice for lenses because most people do not want to put up with the extra weight of a Glass lens, and with a scratch resistant coating and proper cleaning they will last for a good amount of time.

Polycarbonate lenses are thinner and lighter and are shatterproof, most optical,s
you go to will also call them impact resistant which is the same thing.
You can take a hammer and smack a polycarbonate lens with it and it will not break,
so they are the safest lens when it comes to impact resistance, but once you smack it with that hammer you will not be able to see through it because it will be scratched up and dented.
Polycarbonate lenses are very soft and pliable that's why they're impact resistant,
but they also scratch the easiest, so it is a must that you use proper cleaning methods with a polycarbonate lens or their only going to last about 10 minutes.
And for some people they have some inherent distortion that they cannot tolerate,
also some people complain about chromatic aberrations as well.
So although they are the safest you are going to sacrifice some visual acuity with a polycarbonate lens.

I specialize in prescription safety glasses, and being in a safety environment, one of the things I'm faced with when I am sitting down with a safety director to discuss their prescription eyewear program is what type of lenses should we use?
You would think that in a safety situation you would want polycarbonate lenses for your safety glasses because they are the most impact resistant therefore the safest.
And in some cases that is true. But what if the workers are in a really dusty dirty or greasy grimy work environment?
The polycarbonate lenses are going to get so scratched up very quickly that now the worker cannot see through them. So is that safe if they can't see through them?
In a case like that their really better off with a Glass lens.
That way they are easier to keep clean so they can see better which makes them safer.

In summary, what you really have to do is ask yourself what is important to you,
what are your cleaning habits, and in the case of safety eyewear, what type of environment are you going to be using these glasses in?
Are you going to take good care of your glasses? Or do you know that you're not very good at cleaning them properly.
Is it impact resistance and safety that you are after?
Or do you want the best visual acuity, and if so are you willing to put up with the extra weight of a Glass lens?

So, although as I stated before I somewhat agree that we have been brainwashed,
I can't honestly say everybody should be wearing Glass lenses.
Glass lenses are not for everybody nor are plastic lenses or polycarbonate.
As I have always stated in prior post or face-to-face with my customers,
you have to educate yourself to the different choices available in eyewear and then
You Choose what is best for you!

As always, I hope this has been helpful.
I encourage any comments or questions in regards to regular glasses or prescription safety glasses, please feel free to visit my web site, where you can go to the “contact us”
page there you will find my phone number and my e-mail address.

See you next time

Ben…..aka MobileEyeGuy

http://www.mobileeyeguy.biz/

Thursday, August 04, 2005

Why isn't my Eyeglass Exam good for Contacts too?

Once again, thank you for all your comments on the last
“Do I really need that” post.
As I stated the comments brought forth some great questions,
and were going to address one of those in this post.

I hope the person that posted the comment doesn't mind me using it for this post.
But I think it is a question that a lot of people have, and that is why I wanted to use it as a basis for this post, it read like this:

“ This is useful considering I need a new pair of glasses. Actually, I prefer contacts, but I need a new pair of those as well, and the insurance won't cover the cost of the exam. Ridiculous. The insurance will pay for the lenses, will pay for the regular eye exam, and will pay for the glasses, but it won't pay for the measurement for contacts. Why is it a separate charge, anyway? Why isn’t it just part of the exam? Not fair.”

OK... Let's talk about this a moment, I am not going to say whether it is fair or not, but I am going to explain why they consider it too different types of eye exams.
In fact, there are actually three types of eye exams.

1. Eye exam for eyeglasses

2. Eye exam for contact lenses

(commonly know as a Contact lens fitting)

3. Eye exam for pathological problems

(usually given by a Ophthalmologist)

First off let's understand the difference between the three O’s.
An Ophthalmologist holds a doctorate of medicine (M.D.). These doctors have an intimate knowledge of all types of eye conditions and diseases, and can perform eye surgery when required.
They do more of a comprehensive exam looking for problems such as glaucoma, retinal detachment, cataracts etc. You can get an eyeglass prescription from these guys, but it is usually going to cost a lot more, and the doctor himself very rarely does the eyeglass exam, his technician does it and he signs off on it.

Optometrists hold a doctor of optometry degree (O.D.). Optometrists typically diagnose vision limitations, prescribe corrective lenses, and when vision disorders are present, refer patients to ophthalmologists.
These are the guys that are giving you either and eye exam for eyeglasses, or an eye exam with a contact lens fitting so they can give you a contact lens prescription.
Their eye exams are usually much less expensive than the ophthalmologists, and they do the eye exam their self rather than they're technicians doing the eye exam.

Opticians specialize in prescription eyeglasses. In certain geographical locations, they can distribute and fit contact lenses as well.
In some states it is mandatory for opticians to be licensed, and in some states it is not required. Opticians are like a pharmacist they fill the prescription.


That is what I am, I am an optician and licensed by the ABO.
That means I have passed a board exam to prove my competency set forth by the ABO.
ABO stands for “American board of opticianry”, so when I write my name it looks like this:
Ben Ramsey A.B.O.C. which means American board of opticianry certified.

Now, in my opinion if you are not having any pathological problems with your eyes, and all you want is eyeglasses or contact lenses then go to an optometrist.
The eye exam will be a lot less expensive and usually they're a little bit better at correcting your vision.
Please do not misunderstand I am not saying anything negative about ophthalmologists,
it's just that when they give you an eye exam they are looking at you from a surgeon’s point of view, and are looking more for pathological problems than just a refractive error.
And if you're not having any other problems besides just not seeing as well as you would like there is no sense in paying the extra money to go to an ophthalmologist versus the optometrist.

Back to the original question.
Why isn't my eye exam good for contacts too?
When you get an eye exam to correct your vision they put you in the chair and have you looked through the thing-a- majig , and say which is better number one or number two. Right?, then you tell them which one looks better to you.
This is called a subjective exam, you are making the choice of what looks better,
which in turn enables the doctor to diagnose what power your corrective lenses need to be.
But if you want contact lenses that power is going to be slightly different because instead of your corrective lenses being several millimeters away from your cornea suspended in a eyeglass frame, the corrective lenses are going to be laying directly on your cornea.
So that is going to change the power slightly. Plus, they also need to establish what size and what kind of contact lens is going to fit you.
They have to know what base curve you require how much liquid versus oxygen content your eye needs etc.
Unlike eyeglass lenses contact lenses are not standardized.
Because everybody's eye is not the same size or shape there are several different types of contact lenses, so the doctor must establish what size and shape and style of contact lens is best for you.
If you're a first-time wearer you may have to try a couple of different styles of contacts to find out which one is best for you, which may require a couple of follow-up visits.
So the point is, being fitted for contact lenses is more time-consuming than just a simple eye exam for glasses and that is why a contact lens fitting is more expensive than an exam just for eyeglasses.

Therefore most insurances don't what to pay the extra cost for the contact lens fitting.
They usually want the patient to pay a copayment to cover the extra charge.
I guess their philosophy is their job as an insurance company is to correct your vision with eyeglasses, but if you want contact lenses they consider that a luxury and do not want to
pay for it.
Again I'm not saying whether or not this is fair, I'm just saying that's the way it is.
I have heard of some insurance companies paying for contacts but then you have to buy your own eyeglasses.
It is very rare that I have ever seen an insurance company pay for eyeglasses and the contact lenses both.

As always I hope this has been helpful, feel free to post any comments or ask any questions that you may have regarding this post or any other optical questions.
You can also visit my web site, and go to the contact us page, there you will find my phone number and e-mail address feel free to contact me.

See you next time
Ben.... A.k.a. mobile eye Guy

http://www.mobileeyeguy.com/