The optical centers of the lenses should be positioned to suit the requirements of the shooter (head position on the stock etc.) which is why it only makes sense to order lenses after sitting down with a good optician who can see where the centers should be located. That's one reason shooting lenses are so much larger than street lenses. Shooting glass frames should also allow for the lenses to be positioned higher than normal on the face to keep the eyes more centered in the lenses when the head is on the stock.
Prescription lenses and a 15 year old boy:<ul><LI>his prescription will change as his eyes mature<li>his face/head will change shape as he grows<li>the optical center may may need to be moved if he changes guns<li>the lenses may need to be replaced due to scratching or other damage</UL>How quickly any/all of this occurs is anybody's guess.
Im am going through all the same questions as you have with my 12 year old daughter. I talked to several people ( optomitrists) and as MK said- yes things will change as he gets older- just like his regular glasses- what is good today probably wont be good in 2 yeras as his eyes change and his face/ boby size grows.
We ended up getting Randolph Randers from Morgan Optical in new york ( you can google them) - Ask for Wayne. He is an optomotrist and a trap shooter - so I found him to not only very knowledgable but patient and helpful- he will aslo be able to help determine best lense color for your shooting environment.
I do agree with a post that said get a set of glasses that the lenses can be popped out and replaced easily - so at least you are not having to get new frames as often- but again as he grows - if he stays with the sport - you might eventually have to get bigger frames too
For your information: Your shooting glasses should be ground to where your eyes are when you have the beads lined up on your shotgun.
On a right handed shooter for example the centers are ground in the upper left of the lens, by that I mean, not clear up to the top of the lens, but upper of the center of the lens.
You have to have your gun mounted with a plano lens and then the optometrist
will put a dot on the lens at pupil center.
This is done for Maximum vision. I have this done when I get new lenses and Clarence Willis of Custom Sportswear and Optical does this when getting fitted for new lenses.
Once you have a pair made this way it is easy for him to find the center from your old lenses and transfer to new lenses.
I am near sighted and know how important it is. Also he puts the PD Pupil Distance on the Rx and most places like Walmart Eye Glass Center, Lens Crafters Etc do not do this.
My first pairof shooting glasses were made by a Trapshooter and Optometrist from Union Health Center in Dayton Ohio, watched the lenses beiing ground and fitted to my frames, they were Photo Gray's and adjusted to the light.
I picked them up at 3:00pm and went to Camp Troy gun club and shot the night shoot and Broke 50 straight and won over $4000.00 the first time I shot with them.
In glass lenses my Rx is thick and heavy, with the advent of plastic lenses it was a dramatic weight difference, no more sore nose from the eyeglass pads.
There is a limit to how much of a prescription the Decot snap-in frames will accommodate. The stronger the script the thicker the lenses will be on the edges. The clips on the frame may not bend far enough to keep the lenses secure.
You may also inquire about Tryvex lens material: half the weight and thickness of CR-39 plastic with shatter resistance equal to or better than lexan.
The lens manufacturer (lab) will make the lenses to order spec. Your favorite eye poker will measure your PD (pupil distance)in MM. Its not uncommon to have one eye different from the other in distance from the center of your nose. The lab will base where they center the correction prisms based on the clients PD. From that point, the shooting frame sets the optical centers up where a shooter needs it for looking down the rib. Offsetting the optical centers left or right can be done. But a caution, Offsetting makes the glasses uncomfortable to wear anytime other than when looking down the gun. If your one of those shooters that put his shooting frame on when they get to the range and wears them all day, you will not be looking through the prism centers when you use them for or like street use. A 2mm offset is a lot. 4 to 6mm is usually what is needed for shooters that mount a stock a bit sideways(my terminology for someone that mounts looking out of the top corner of lenses).
Our eyes naturally or inherently try to see clearly all of the time. With or without a correction, including a variance in correction. To prove that just move your glasses around on your face to see the optic and its clear spot. If your not looking through the correction optic centers, your creating eye strain. The optic is the size of a dime to a nickle depending on Rx. Even plano lenses have a sweet spot based on curvature. I do offsets for shooters, but caution them. Personally, I choose to set the prism centers like street glasses and raise those by frame for shooting. Thsi to not create eye strain during the day. Have set my LOP so to be able to square up with the barrels rib, looking lower and more centered to the lenses/frames.