Vari Focal
Bi-vocals vs Vari-focals ?
Does anyone wear vari-focal glasses ?
What are the pros and cons versus bi-focals ?
Bifocals (with the line) have been around since the days of Ben Franklin (he invented them!) and they are becoming obsolete. Lined bifocals only give you a correction for 2 distances; far away (beyond 20 ft. or so) and up close (18 inches and closer) And because they only have two corrections in the lens, they are easier for most people to adjust to. They do still require a period of adjustment but often times it happens much sooner for most patients.
What about objects in between? Lined bifocals offer nothing for a computer screen, or even seeing objects on the shelf at the grocery store. To see a tag on the shelf at the store, people typically have to either take a few steps back to see it through the top portion of the lens, or tilt their head WAY back and get closer to the tag to use the reading portion of the lens.
Also with the lined bifocal, you have a huge jump in the prescription. As your looking down through the lens, its goes from far away, to upclose…very abruptly. Not smooth and gradual.
That line also can catch a lot of glare, because you can feel that line on the surface of the lens. Its ground into the surface and causes a little edge, which when catches the light just right, you get a glare from it.
And not to mention the fact that *most* people think that line is unsightly and they usually aren’t ready for the world to know that they are getting older. So from a vanity stand point, lined bifocals are not the best thing for people who are in denial about their age! LOL
Varifocal lenses, also known as progressive lenses or no-line bifocals are a much more versatile lens. They give you the same near and far prescription, but they also give you a prescription for everything in between and for this reason, they are closer to your natural vision. The human eye is meant to see clearly at all distances; not just up close and beyond 20 ft. Progressive (varifocal) lenses acheive this. So now, you have a lens that you can drive in, read in, use your computer, shave, and pretty much anything else. The prescription runs in a channel in the lens (usually its kind og mushroom cloud shaped) and in order to use them properly, all it requires is a slight head-tilt. To see to drive, you may have to tilt your head down slightly (I’m talking a few degrees. You shouldn’t have to bury your chin in your chest to see clearly to drive. If you find that you must do this, it means the lenses have been measured too high) Then to see things at other distances, you’ll have to tilt your head a few degrees accordingly, depending on how far away it is. Again, it should only be a few degrees. And the clearest part of the lens is always when your looking through that channel I mentioned…which means you must point your nose at what you are looking at in order to see things the clearly. Off to the sides of the lens there is some distortion. There are lenses available that have minimal distortion and those are better than just a standard lens. Less distortion equals easier adaptation to the lenses, which is another story all together.
The reading portion of the lens works similarly to the old lined bifocal; just drop your eyes and your reading area should come in.
Because of all of the prescriptions in the progressive lenses, and because there is a certain way to use the lense in order for a person to be successful, they do take longer for *most* people to get used to. I find that some patients are slow to grasp the concept of having to tilt the head, and point your nose at what you’re looking at. There is a knack to it and most patients make the adjustment within a week or two. There is the occasional person that takes an inordinate amount of time and comes back in to our office several times because they are having problems adjusting. The majority of patients who get progressive lenses (varifocals, whatever…) do very well with them and are pleased with their convienance and versatility. You get a person every now and then who cannot wear them successfully. And in my opinion, most of those people who claim that they can’t use them are either not using them properly, or aren’t wearing them enough. People expect to be able to pick them up and see perfectly right away without any adjustment period necessary. In order to adjust to the lenses, one must pick them up and wear them as much as possible; not just for an hour here and there. You need to build up a tolerance and retrain your eyes and head on how to use them and you cannot do that in an hour here and there. It takes some time and patience…and those are things that a lot of unsuccessful progressive wearers refuse to invest in their glasses.
Progressive lenses are not for everyone and there are certain circumstances where I would tell a person that perhaps they aren’t for them.
A patient who is 70+ who has worn lined bifcoals for 20 years already, usually (not always) has a very difficult time with getting used to them.
People who need very large reading areas, like architechs who use blue prints, typically need a larger reading area than a progressive lens offers. Not always, but *usually*.
Also, roofers or construction workers…up on tall buildings and scaffolds…progressive lenses can be tricky for them.
But generally, progressive lenses work out well for probably 90% of patients. They are a little more expensive, but they offer so much more to the patient. Its like having 3 different pairs of glasses all in one; one for distance, one for reading, and one for the computer. So when you think of it that way, they really aren’t as expensive. The difference is that you’d have one pair of glasses that does the job of three so there is only one pair to wear and keep track of, which is really nice for most people who are carrying around multiple pairs because they don’t have one pair that does it all.
Hope this helps!
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DOME 1/3″ SONY CCD COLOR IR VARI-FOCAL VANDAL CAMERA $43.99 |
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Computar TG2Z3514FCS-2 CCTV Lens 3.5-8mm F1.4 Vari Focal $53.00 |
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SONY 600TVL CCD Vari-Focal 4-9MM IR Weatherproof Camera $69.95 |
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Security Camera High Resolution Sony CCD Infrared w/ Vari-focal Lens $34.99 |
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PANASONIC PLZ27/5DN CS MOUNT VARI-FOCAL LENS W/ AUTO IRIS DC, 2.7-13.5mm $50.00 |
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420 TV Lines COLOR DOME IR VARI-FOCAL VANDAL CAMERA $57.99 |
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Computar , Vari focal Mini connector TG10Z0513FCS-2 $34.99 |
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NIB TOSHIBA FUJINON FUJIFILM VARI-FOCAL CTV LENS YV2.8X2.8LASA2L 2.8-8mm F0.95 $29.99 |
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Vari-focal 100′ IR Dome Camera with Audio $79.99 |
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Vari-focal 420TV Line Sony CCD 65′ IR Indoor Night Vision CCTV Camera With Audio $74.75 |
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Capture CCTV SN-VPB4840 Vandal-Proof Vari-Focal Dome Camera $91.64 |
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AXIS M3204 NETWORK CAMERA DOME TAMPER-PROOF COLOR FIXED IRIS VARI-FOCAL 0337001 $561.07 |
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SONY 600TVL CCD Vari-Focal 4-9MM IR Weatherproof Camera $69.95 |
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10 LED IR True D/N Vari-Focal 420TVL, SSM-742AII $151.36 |
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10 LED IR True D/N Vari-Focal 550TVL, SHM-755AII $171.35 |
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10 LED IR True D/N Vari-Focal 420TVL, SSM-742AII $157.49 |
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10 LED IR True D/N Vari-Focal 550TVL, SHM-755AII $194.82 |
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4Ch DVR & 4xIR Bullet Camera (2.9~10mm Vari-Focal) Package $695.20 |
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82-14330 Weather-Resistant Long-Range Vari-Focal Dual Lens Bullet Camera $338.87 |
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New DBM-20VDL CCTV Built-In Vari-Focal Lens 600TVL $115.00 |
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0.001 Lux Starlight 650TVL CCTV Board Camera Vari-focal Lens 3D-DNR D-WDR $66.00 |
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HAWK-I HAWK561VXIRCB Color IR Bullet Style, Vari-Focal 4 -9mm, High -Resolution, $99.99 |
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Panasonic WV-LZA61/2S Vari Focal Zoom Lens 3.8 mm – 8 mm F/1.4-1.8 $59.99 |
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CCTV CCD Surveillance Cam Vari-Focal IR Security Camera $63.99 |
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Vari-Focal 3.5mm-8mm CS Security Camera Lens, Manual $29.00 |
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Vari-Focal AUTO-IRIS 6mm-15mm, CS Security Camera Lens $49.95 |
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Vari-Focal AUTO-IRIS 5.0mm-100mm Extreme Zoom lens cctv $94.00 |
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V2262D – Outdoor Vandal Resistant Vari-Focal Dome Camera $150.75 |
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Vari-Focal AUTO-IRIS 2.8mm-12mm,CS Security Camera Lens $59.00 |
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V3363D – Kaltech High Resolution Vari-Focal Vandal Proof Dome Camera $174.25 |
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Vari-Focal AUTO-IRIS 3.5mm-8mm,CS Security Camera Lens $44.00 |
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Vari-Focal AUTO-IRIS 6mm-60mm,CS Security Camera Lens $75.00 |
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LEN0660 1/3Vari-Focal Lens 6.0 – 60.0mm DC Driver lens $49.99 |
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LEN3580 1/3 Vari-Focal Lens 3.5 – 8.0MM DC Driver lens $25.99 |
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LEN2812 1/3 Vari-Focal 2.8 – 12.0MM lens DC Driver lens $39.99 |
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480 Vari Focal Metal Security CCTV Surveillance Camera $74.99 |
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NEW DVT Computar Vari Focal LCC-05Z LCC05Z 5-50mm F1.3 $175.00 |
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SONY 600TVL CCD Vari-Focal 4-9MM IR Weatherproof Camera $69.95 |
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540TVL 1/3 Sharp CCD Vari-Focal 4~9mm manual Len IR Dome Outdoor Security Camera $72.10 |
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SONY 600TVL CCD Vari-Focal 4-9MM IR Weatherproof Camera $69.95 |
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560TVL Sony CCD Dome Outdoor CCTV Security Camera Vari-Focal 4~9mm 0 Lux 82ft $75.95 |
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600TVL SONY CCD CCTV IR Dome Indoor Security Camera Vari-Focal 3.5~8mm Len 36 IR $87.40 |
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520TVL 1/3″ Sony CCD Dome Outdoor Security Camera Vari-Focal 4~9mm 30 IR LED $75.95 |
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650TVL 1/3 Sony CCD 4~9mm Vari-Focal Len 36 IR LED Dome Indoor Security Camera $90.25 |
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(4) 1/3″ SONY CCD Vari-Focal Surveillance CCTV Cameras $368.00 |
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IC REALTIME EL720: Indoor Vari-Focal Dome Camera $250.00 |
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700TVL Sony CCD IR CCTV Dome Outdoor Surveillance Camera Vari-Focal 4~9mm Len $109.25 |
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4-9mm Vari-focal 65′ IR Indoor Dome Camera with Audio (CM-S22129BG-AD) $72.49 |
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650TVL, Korea Vari-focal D/N Dome Cam Sony SuperHad CCD $180.29 |
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High Resolution 650TVL Vari-focal Indoor Camera with 65′ IR (CM-S22719BG-AD) $99.99 |
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6- 60 mm 60MM CCTV Camera Lens manual Iris Vari-Focal NEW $44.99 |
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KARE Lot 4 480TVL Vari-focal CCTV Security LED IR Camera w/ SONY CCD 60FT Cable $110.00 |
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Sony CCD 540TVL Waterproof Outdoor IR Vari-focal Dome Camera 3.5-8mm Lens $94.99 |
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Mini Vandal Dome Vari-focal camera Sony 540 line 40m IR $133.22 |
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Pelco MCC1380H-6 1/3-inch CCD Camera w/ Pelco 13vd 2.8-12mm vari-focal AI lense $200.00 |
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EFFIO-E 700TVL 2.8~12MM VARI-FOCAL LENS 1/3 SONY EXVIEW HADII CCD HD IR DOME $100.00 |
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VARI-FOCAL INFRARED HIGH RESOLUTION CAMERA suveilance Security sony CCD 0 lux IR $75.95 |
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Vari-Focal 1/3″ Sony CCD IR Vandalproof Weatherproof Security Camera with Audio $79.99 |
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1/3″ Sony CCD 420 TV Lines 4-9mm Vari-Focal Lens IR Security Camera with Audio $74.75 |
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Two Vari-focal IR Color Bullet Cameras $25.00 |
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COMPUTAR VARI FOCAL TV LENS TG2Z3514AFCS-2 $29.99 |
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13VD5-40 Pelco 1/3″ Format Vari-Focal Zoom, 5-40mm Auto Iris NEW $76.50 |
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(4) VARI-FOCAL 1/3″ SONY CCD SURVEILLANCE CCTV CAMERA $370.45 |
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SONY 600TVL CCD Vari-Focal 4-9MM IR Weatherproof Camera $69.95 |
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Clover HDC560 OUTDOOR VARI-FOCAL, NIGHT VISION CAMERA $299.00 |
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IRIS VARI-FOCAL DOME CAMERA NTSC $775.00 |
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Nikon Vari focal View Finder 2.8cm 28mm Wide Angle Attachment rangefinder $899.99 |
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Used Nikon Vari Focal Zoom Finder 35-135mm (SN 340600) finder rangefinder EP $512.99 |
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Panasonic PS-POC244L5DW-Camera Kit w/ Vari-focal Lens – Kit $365.67 |
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Tamron CCTV Security Camera Lens 6-12mm Vari-Focal ** FREE SHIPPING** $18.49 |
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1/3″ DSP Color Vari-Focal Vandal Proof Dome Camera -FREE SHIPPING! $99.99 |
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Computar TG3Z2312AFCS CCTV Camera 1/3″ Video Drive Vari Focal Lens 2.3-6mm 1:1.2 $30.25 |
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Computar HG2Z4516AFCS-2 CCTV Camera 1/2″ Video Drive Vari Focal TV Lens 4.5-10mm $25.50 |
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Bosch Lens LTC 3374/20 | 1/3″ CS-Mount 5-50mm Vari-Focal Lens with Auto Iris DC $14.99 |
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DVCCMDNV668H – Vandal Proof Vari Focal 36IR Dome Camera $114.25 |
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Computar Vari-Focal Camera Lense 3.5 – 8mm 1:1.4 1/3 CS CCTV $21.95 |
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1/3″ 5.0-100mm 7.6-16.6mm Back Focus Auto IRIS(DS) Vari-Focal Camera Lens $46.99 |
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1/3″ Sony CCD Vari-Focal Vandalproof 100’ IR Outdoor CCTV Audio Security Camera $79.99 |
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Security Box Camera Lens 1/3″ 2.8-12.0mm Auto IRIS Vari-Focal Lens Zoom & Focus $33.99 |
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1/3″ Sony CCD 420 TV Lines 4-9mm Vari-Focal Lens IR Security Camera with Audio $74.75 |
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3-AXIS IN/OUTDOOR 4-9 MM VARI FOCAL INFRARED BULLET CAMERA Sony CCD Bullet $49.95 |
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BOSCH Vari-focal IR Lens LTC 3664/30 $95.00 |
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1/3” Vari-Focal 2.8~12mm Lens F1.4, CS Mount Auto IRIS $64.95 |
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1/3” Vari-Focal 3.5~8mm Lens F1.4, CS Mount Manual IRIS $49.95 |
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1/3” Vari-Focal 6~60 mm Lens F1.6, CS Mount Auto IRIS $74.95 |
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NEW CLOVER HDC211 TRUE DAY/NIGHT VARI-FOCAL COLOR DOME CAMERA $224.75 |
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CCTV Surveillance 600 TVL Vari-Focal Weather IR Camera $169.99 |
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Sony CCD 550 Lines CCTV Security Camera Vari Focal IR $185.00 |
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Sony CCD Hi Res Dome Vari Focal Security CCTV Camera $139.00 |
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Sony CCD High Res CCTV Security Dome Camera Vari Focal $149.00 |
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IC REALTIME ICR-149 BULLET CAMERA CCTV Surveillance Color 3.5mm-16mm Vari-Focal $79.00 |
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Zoom & Focus 1/3″ 2.8-12.0mm Auto IRIS Vari-Focal Lens Security Box Camera Lens $34.99 |
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1/3″ 5.0-100mm F1.6 -360° Aperture Range Auto IRIS(DS) Vari-Focal Camera Lens $47.99 |
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6 – 15 MM CCTV Lens CS manual-Iris Vari-Focal w/Lock $179.99 |
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Lot 8 pcs 6 -15 MM CCTV Lens CS Auto-Iris Vari-Focal DC $199.00 |
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VideoSecu CCTV Dome Weatherproof CCD Vari-focal Lens Security Camera $189.95 |
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1/3″ 5.0-100mm 7.6-16.6mm Back Focus Auto IRIS Vari-Focal Camera Lens $48.99 |
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1/3″ 2.8-12.0mm Auto IRIS Vari-Focal Lens Zoom & Focus Security Box Camera Lens $34.99 |
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1/3” SONY Super HAD CCD II 480 TVL 2.8~10mm Vari-focal Manual Iris Dome Camera $99.99 |
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Q-See QD6503X Elite Box Camera – CCTV camera – color – vari-focal – 650 QD6503X $190.99 |
