The Private Pilot tests were set up by journalists in order to sell magazines. ... Ask you optician sister whether a 0.24D lens in front of your eye will cause any discomfort or hazard.
I don't have to ask my sis; I remember a fair bit of it from reading her textbooks... Let's look at p.2 of the 2003
Private Pilot test, left-hand side...
The D would be
dioptre - the scale that corrective lenses are measured on. If you wear glasses or contacts and you're familiar with your prescription, the +2.5 or -3.25 or whatever yours might be is expressed in dioptres. Meridian 1 and 2 would be this measurement taken across two planes on the lens - probably, but not necessarily, horizontally and vertically. Astigmatism would be the difference between these two measurements. It logically follows that any measurement ≠ 0 implies that the lens is changing your eyes' natural focal point. However the contacts I wear are available only in .5 increments, so these numbers are small enough that I'm happy to consider them irrelevant. It is the one measure where even the ANSI standard allows for very little variance...
If we look at the next set of data we see measures for prism correction, i.e. the amount that a lens would shift the apparent position of an observed point. If I recall a lens rated at 1Δ would shift the apparent position of a point by 1 unit for every 100 units between the lens and the observed point. It follows that a reading of 0 would be ideal. Interestingly ANSI Z87.1 allows for up to .5Δ with certain limitations - a little worrying, as it implies that something 200m away from you could appear a whole meter away from where it actually is. That could make driving at speed and/or long distance, or landing a plane, quite tricky.
Never mind the implications for eye and brain strain if you need to observe far away objects for extended times, which your two eyes each perceive in different, but equally wrong, positions. Such goggles are probably acceptable for grinding something 50cm in front of your nose though.
I'm sure you can see the value of relative scores for people not at all familiar with these units of measurement.
Here's something: There is indeed an ANSI standard for non-industrial sunglasses -
ANSI / Z80.3 - 2008, Nonprescription Sunglasses and Fashion Eyewear. Furthermore, as can be ascertained from
this lab report, it seems the ANSI Z80.3 requirement for prism correction (footnote on p.7) is only
half that of ANSI Z87.1 for industrial safety goggles... twice as stringent in other words. Must not be as important for factory workers to see things where things actually are as for people driving cars, hitting golf balls and flying planes...
The fact that the ANSI standard for resolution is merely 20 lines resolved on the NBS chart is just another indication that their primary function is that of impact protection. Do you seriously want to contend that having lenses that distort things half as much as the minimum standard for industrial use is not a benefit?
My guess is that the professional standard setters at ANSI, an independent authority ... should you question their choice of minimum standard.
Here's where things start getting funky for you... Let's look at the
Scope and Purpose of the standard as detailed in Uvex's brochure; it kinda reads like it's quoted directly from the standard: "The objective of this Standard is to provide
minimum requirements for eye and face protective devices" Minimum requirements. Heh. Taken with the information provided above, I'd say that's rather conclusive that any optics exceeding the minimum required performance of the ANSI standard would carry a proportional benefit; especially where physical protection isn't the primary concern. You probably shouldn't be driving with safety glasses.
...where does Angel eyewear claim to pass the Z87 tests?
I must confess I didn't take note of where I came across it. It was an obscure .pdf from somewhere in the bowels of the Internet detailing a model produced by
Angel in 2003. It was shoddy information, it was late, I was tired.
Pilots, special operatives, heck even golfers would have different, and in many cases more stringent, requirements for their eyewear than factory workers. They also aren't directly in line to be shafted by corporate industries like factory workers would be - anything to save a buck, you know. Those who are likely to be short-changed need standards to protect them, whilst keeping the resultant product as cheap as possible in order to encourage compliance. The rest of us can do some research in order to decide how to spend our money.
Perhaps you could enquire from the US Armed Forces why Oakley is standard issue - they could probably save up enough to float another couple of Nimitz-class carriers if they just convert to Afrox safety goggles.
...my shades are treated like **** ... Would you prefer me to remove them before I start grinding?
What about if I said ‘please’? Nah, keep them on. They'll do what they're designed to do when you're grinding something - offering you fantastic physical protection whilst not impairing your view so much that you lose a finger. And mine will do what they're designed to do - offering me comfort, almost perfect acuity, enhanced contrast, reduced glare and a polarised view of the world, whilst protecting my eyes from any random ball bearings travelling in my direction at 152 feet per second.
I must confess that you've taught me something - the stamp on your goggles would indeed mean that they've passed all the tests in the standard. I'll keep this in mind in future 'internet is serious business'-encounters...
...I trust my R29 glasses...
Made to a general industrial standard. One which states:
Certain hazardous exposures are not covered in this standard. These include, but are not limited to: Bloodborne pathogens, X-rays, high energy particulate radiation, microwaves, radio-frequency radiation lasers, masers, and sports and recreation. Guess one would be well advised to look elsewhere for any eyewear required to do more than just offer the minimum acceptable level of protection and acuity that big industrial endeavours can get away with.
... FUD marketing... I could write a book...
As long as you're not talking late-night infomercials, not all marketing is FUD. Porsche build genuinely fantastic cars (as confirmed by independent tests), Nokia used to manufacture genuinely fantastic cellphones (as confirmed by independent tests), Oakley produce genuinely fantastic sunglasses (as confirmed by independent tests). If you've managed to rise above all others in your field, you might as well ride that fact for all the marketability it's worth. Add to that the power of personal experience, and subsequent word of mouth marketing, and before you know it you can have a brand like Porsche, Nokia or Oakley. Also, with your rampant apostrophe abuse, your editor would have nightmares.
Nah, I hadn't even bought my first pair of Oakleys when my wife and I started dating, and I buy my clothing at Mr Price... maybe my extraordinary large... erm... feet had something to do with it.
Leave the wife out of it, will ya?
... I make my money building tangible assets ...
Good for you. No, really...
For the record ... Yeah right.
It's only fun until you realise the
women will never let you join in.
Do I sense some commitment issues?
Done and done.
I don't need to impress everyone I walk past ...
Looking like you need a guide dog, whilst deftly navigating around lamp posts like you don't? That'll get old.
To be fair, blu is pregnant & hormonal. I asked The_Librarian to shift our little boxing match this way to avert a possible wobble.
