The guide was intended for the doctor and not for the shooter. I 
recommend that when making the appointment, identify your needs so that 
the office may make special arrangements. Ask for permission to bring 
your pistols to the office and if denied, just bring in the dot scope 
and iron sight slide. Then ask if faxing or mailing a copy of the guide 
prior to the appointment would be helpful. Always obtain the name of the 
person you spoke with and write it down for future reference just in 
case if any problems arises.

 
 

It has been my pleasure to put this guide together for the list and I 
hope that it will draw proper attention from your eye doctors. I did not 
intend for this guide to be overwhelming, otherwise it will not be read 
by your doctors especially those working for an HMO.

 

Regards,

Norman H. Wong, O.D.

 
 
 

Dear Colleague,

 

My name is Norman H. Wong, O.D. and I am a member of the California 
Optometric Association and the American Optometric Association. I am 
also a veteran, a life-member of the NRA and a competitive bullseye 
shooter. Bullseye shooters are a wonderful group of individuals with 
critical visual needs. Please put aside any political views against 
firearms, if any, and treat the bullseye shooter as you would any other 
patient. The patient had asked for permission to bring his/her 
firearm(s) to the office for the eye examination and will demonstrate 
that the firearm is unloaded and safe. If the patient was denied, 
sighting parts of the pistol(s) were brought instead. Take a moment to 
review these important steps before and during your eye examination. 
Besides your routine health tests of the eyes, I have emphasized a few 
areas of concern. Your kind attention to details would be most appreciated.

 
 
EYE  EXAMINATION 
 

1. CASE HISTORY: A thorough case history revealing any medical problems 
which may relate to eye health and vision stability is essential. Note 
all medications taken, including over-the-counter medications and advise 
of possible visual side affects.

 
2. DOMINANCE: Review and confirm eye dominance and hand dominance. 
 

3. REFRACTION: Your best effort is needed to obtain the most accurate 
results. After you obtain your best distance Rx, see if the patient is 
sensitive to 0.12 diopter steps. Please double check vertex distances 
especially for higher powers. Check to see if the patient's line of 
sight is "continually" centered through the phoropter lenses. Do not 
reduce the full strength of the prescription even if there was a large 
change from the previous examination results. Small prescriptions such 
as +0.25, -0.25 diopter sphere and +0.25, -0.25 diopter cylinder, even 
if obliquely oriented, may be significant.

 

4. RED DOT SCOPES: Normally, the best lens for the red dot scope viewing 
would be the best distance prescription. Demonstrate this lens while the 
patient looks at the red dot while holding out the scope. Because the 
red dot in the scope is not focused at "optical infinity" (it is 
closer), try a +0.12 or a +0.25 diopter lens over the best distance 
prescription to see if the dot becomes even clearer. If possible, 
judgment would be best if the patient can view at a distance greater 
than the standard 20 feet and with outdoor lighting. If the dot is 
distorted, use the phoropter once again to verify cylindrical power and 
axis as the patient holds the pistol (or scope only) in front of the 
phoropter. Final results may be demonstrated with trial lenses. If after 
all lens possibilities have been demonstrated and the red dot never 
became clear and round, then a careful determination of ocular health 
involvement needs to be assessed.

 

5. IRON SIGHTS: We are concern with three separate entities, the clarity 
of the front sight, the clarity of the rear sight and the relative 
blurriness of the bullseye. These three positions cannot be focused 
simultaneously with just a lens. The rear sight is separated from the 
front sight by about 6 3/4 inches in most standard 1911 .45 caliber 
pistols. Measure the EXACT distance from the patient's shooting eye to 
the rear of the front sight while he/she is in the proper stance. Write 
this down for the patient's record. Set this distance for the reading 
card on the rod of the phoropter. Find the best lens for this position 
and then try 0.12 diopter higher and 0.12 diopter lower and note if the 
patient responds to this small change. Presbyopic patients will give 
good responses. For the pre-presbyopes, low power lenses may allow for a 
more stable focus. Younger patients under 35 years of age may benefit 
from a minimal plus power for a steadier focus, or perhaps none at all.

 

The patient needs to know the best plus lens because there are specialty 
type shooting glasses with interchangeable lenses. The two popular ones 
are Knobloch Optik and Neostyle Champion systems which include lenses, 
occluders, apertures and side blinders. There are a number of lenses 
available with these systems (+0.50, +0.75, +1.00, +1.25, +1.50). The 
base lens (patient's distance prescription) can be custom made at the 
optical lab to incorporate into this system. This interchangeability 
allows for a quick change when different powers are needed for various 
shooting distances and lighting conditions. Personally, my best lens for 
the front iron sight stays the same under day and night lighting 
situations. In my case and in many other patients', we prefer a 
dedicated pair of shooting glasses for the iron sights, which may also 
be helpful as a computer Rx and for other hobbies at a similar working 
distance.

 

Next, have the patient view this best lens with the pistol in hand at a 
distance greater than 20 feet, and if possible, outdoors at 25 and 50 
yards. Majority of offices may have limitations. Depending upon a few 
factors such as arm length and pupil size, typical lenses that work best 
are +0.50, +0.75 and +1.00 diopter over the best distance prescription 
but also try +0.37, +0.62 and +0.87 diopter lenses even though these are 
uncommon powers. You may be surprised how sensitive some shooter's eyes 
may be. In my case, +0.75 diopter is my ideal lens. A +0.62 diopter lens 
blurs the rear sight and a +0.87 diopter lens blurs the bullseye too 
much. Experienced shooters would know that the distance bullseye will be 
out of focus. As different lenses are tried, this will allow the patient 
to compare the relative blurriness to the bull. Stress that front iron 
sight clarity is more important than the bull clarity. Most shooters 
know that an adjustable aperture will then help clear the bull.
l. When too much emphasis is given to the bull clarity, then the rear 
sight clarity will be compromised. The patient will always shoot better 
if the front and rear sights are perfectly clear and aligned while the 
bull is blurred rather than if the bull is clear and the sights cannot 
be seen well enough for proper alignment. Always use the lowest plus 
power lens to achieve this goal.

 

As a quick reference guide, here are the focal lengths of the powers 
discussed:
+0.37 diopter: 2.66 meters
+0.50 diopter: 2 meters
+0.62 diopter: 1.6 meter
+0.75 diopter: 1.33 meter
+0.87 diopter: 1.14 meter
+1.00 diopter: 1 meter
Lens determination by focal lengths alone may cause erroneous results. 
This should be used only as a starting point.

 

6. BINOCULARITY: Advise the patient if there are any binocular problems 
which may affect focusing stability. Most shooters occlude one eye but 
some shoot with both eyes open and suppresses the non-dominant eye. 
Hyperopic patients who are esophoric may have more of a difficult time 
if eyeglasses are not worn. Again, low power lenses need to be 
prescribed if the patient desires clear and stable focus.

 

7. CORNEA: Carefully inspect for any corneal defects including beginning 
signs of keratoconus. Note and advise the patient of any old scars and 
dystrophies along the visual axis which may compromise the focus of the 
red dot. Check corneal curvatures with the keratometer or use corneal 
topography for irregularities. Check the tear film and advise of any 
possibility of dry eyes which may cause unstable focus. Recommend dry 
eye therapy as needed. Use of ocular lubricants may be beneficial before 
and during shooting.

 

8. LASIK and RADIAL KERATOTOMY: Foreign matter introduced in the 
interface and other complications during LASIK procedure may or may not 
affect vision. Advise accordingly. Irregular astigmatism may result from 
radial keratotomy and distort the red dot. Frequently, we will have an 
undercorrection or an overcorrection after surgery and the full lens 
prescription needs to be given.

 

9. CONTACT LENSES: Patients correctable to 20/20 or better frequently 
see only 20/25, 20/30 or worse with contact lenses. This may be due to 
small uncorrected astigmatism, contact lens surface deposits, or 
desiccation of the soft lens material. Contact lens lubricants may help 
when used before and during a match. A shift in vision may be noted when 
toric contact lenses rotate. These minor problems may be acceptable to 
the patient.

 

10. PUPILS: Note if the patient's pupil is unusually small or large. A 
small pupil will allow for a longer depth of focus but may cause more 
symptoms with lenticular opacities. A wide pupil will cause a short 
depth of focus and will make our job a little more challenging to find 
the best lens possible. As the amount of ambient light changes 
throughout the day, the pupil size will also change and may give 
different sighting appearances. Inspect the iris for colobomas and for 
trans-illumination defects which may cause diplopia and glare.

 

11. CRYSTALLINE LENS: Note and advise the patient of any lenticular 
opacities which may affect the viewing of the sights. Commonly seen 
opacities may not affect the non-shooters but will affect the shooters' 
clarity of the red dot or iron sights. Senior patients who have had 
intra-ocular implants need to be closely inspected for signs of 
posterior capsular opacities.

 

12. MACULA: Closely inspect the macular area for any signs of defects 
including ARMD. Use of Amsler Grid may be helpful.

 
 

EYEGLASS SELECTION

 

1. LENSES: Review past lens types and materials used. Discuss what has 
worked and what has not. Review ABBE VALUE of various lens materials and 
possible distortions especially in higher powers. Polycarbonate is the 
only FDA approved safety material that is widely used today and is 
always recommended as the first choice. Other materials may be used ONLY 
with the patient's understanding that they are not approved safety 
materials. If needed, the patient may be required to sign a waiver of 
responsibility. Many patients choose to have a dedicated pair of 
shooting glasses which should be polycarbonate and then other materials 
may be used for their dress eyeglasses. Note that Knobloch Optik and 
Neostyle Champion lenses come only in CR-39 plastic. When writing up the 
lab order, request for "exact power required" and reject lenses that are 
not exact even though they fall at the limits of the ANSI standards of 
power, +0.12 and -0.12 diopter.

 

2. EYEGLASS FRAMES: Frames should not be too small and flimsy such as 
rimless. Safety frames following ANSI standards would be best. 
Wrap-around style frames may require steeper base curve lenses which may 
cause distortions. Some sports frames which have a one piece curved 
front shield may have inserts which will allow for the patient's 
prescription lenses. These goggle type frames have no adjustability, 
important with moderate to high prescriptions. Being that there are four 
surfaces, fogging and cleaning may be a problem.

 

3. MULTI FOCAL HEIGHT MEASUREMENTS: Have the patient demonstrate their 
head posture while at their "shooting stance" as you take the proper 
height measurements. Extreme diligence needs to taken so that the line 
of sight is not impeded by the near or intermediate portion of the lens. 
When measured correctly, there should be no restrictions with bifocal, 
trifocal and progressive lenses. Verify that the measurement taken with 
the shooting stance is also compatible with the patient's normal daily use.

 

4. ANTI-REFLECTION COATINGS and ULTRAVIOLET COATINGS: Discuss the 
advantages of AR coatings which will reduce glare as well as reflections 
and UV coatings for blocking harmful UV rays of the sun.

 

5. TINTS: Kalichrome (yellow) enhances contrast but offers very little 
shading and may be helpful in low light settings. PLS 530 (orange) and 
PLS 540 (orange-brown) are tints which block all wavelengths above their 
stated levels. I have found that it is best for the patients to view 
tint samples and have them report what is most comfortable. Transitions 
photochromic lenses lighten and darken with the amount of direct 
sunlight and its usage is very convenient. Avoid "fashion tints" which 
have no protective qualities. If possible, loaning samples for the 
patient to view at the range would be most helpful.

 

I am constantly learning more of the bullseye shooter's needs as I 
continue to participate in this rewarding sport and have been revising 
and adding onto this list. I will, from time to time, update this list 
as needed. Bullseye shooters are intelligent, honest, law-abiding 
citizens with much character. You now also have a very happy patient and 
we invite you, your family and friends to join us and see what BULLSEYE 
SHOOTING is all about.

 

Regards,

Norman H. Wong, O.D.


2/05