Humphrey Field Analyzer II lens holder

[Ory]

Hey,

I have a HFA II with a cracked trial lens holder. I've superglued it (is there anything superglue can't do) but would like to replace it. Anyone ever replace one? The arm is fine so it's just the little holder - can I replace that part only, by myself, without paying a "technician" lost of bucks?

Thanks!!

[BioMed]

Is it the arm or Lens itself? If arm is damaged you're going to need service for correct calibation. If its the lens you can follow what I wrote, of which some technical dexterity is needed. Loosen front two screws on front cover (patient support assy). Pull from bottom and out slightly, then gradually lift out while pulling from top. While holding front cover disconnect ribbon cable and ground wire. There are two small socket hex screws securing it to the arm. Now the trick is not to remove arm or your calibration is no good. Carefully lift off arm about 1" cut wires and wrap in tape. Notice staggered position of wires. Continue wrapping onto new TLH. This keeps wires tight to make it easier to pull through frame. Secure new TLH and reverse the process.

If you have any questions just email me...d.cox@biomed-ics.com

[Ory]

Thanks for the reply. The lens holder is one of the ones with the 2 LEDs (IR?) that are used by the system for positioning - that's why the holder cracked, because the LED mountings are drilled out of the lens holder thus making it weak.

We looked into replacing the lens holder and were told some revolting price for parts and labour and just decided superglue worked well enough. 2 years later and it's still holding!

[DOCJDH]

Is it the arm or Lens itself? If arm is damaged you're going to need service for correct calibation. If its the lens you can follow what I wrote, of which some technical dexterity is needed. Loosen front two screws on front cover (patient support assy). Pull from bottom and out slightly, then gradually lift out while pulling from top. While holding front cover disconnect ribbon cable and ground wire. There are two small socket hex screws securing it to the arm. Now the trick is not to remove arm or your calibration is no good. Carefully lift off arm about 1" cut wires and wrap in tape. Notice staggered position of wires. Continue wrapping onto new TLH. This keeps wires tight to make it easier to pull through frame. Secure new TLH and reverse the process.

If you have any questions just email me...d.cox@biomed-ics.com

You say to carefully lift off arm about 1", I want to make real sure, you mean to say "lift off TLH", not the arm, correct? Am I assuming right that you should not dare loosen the two screws securing the base of the TLH ARM or it will mess with the calibration.

James Hemmig

[DOCJDH]

I replaced my TLH rather easily recently. Zeiss sent the arm and TLH for around $290 - you may have to squawk some to get them to do it.

The wires pop out of the plug and the replacements are fished down the original arm (do not remove it) and reinsert back into the plug. TLH screws on to of the arm.

Was easy to do.

[hansel45]

Are the two screws that you are talking about on the lower part of the front of the machine and recessed quite a bit in tunnels. They look like hex screws that require an Allen wrench? There are also two Phillips head screws just behind the patient support system that hold down a metal cover over the base of the lens holder arm. -Dick Scholz

[DOCJDH]

Are the two screws that you are talking about on the lower part of the front of the machine and recessed quite a bit in tunnels. They look like hex screws that require an Allen wrench? There are also two Phillips head screws just behind the patient support system that hold down a metal cover over the base of the lens holder arm. -Dick Scholz

Sorry, don't recall, just traded in for newer version. As I recall screws were accessed via inside the bowl and were easy to see, however, there was a cover plate needed remove and whole arm removed and cable unplugged. Sorry, this was some time ago.

[hansel45]

What does calibration mean? I do not use the gaze tracking feature at all and the lens holder and arm are one piece. The cracked lens holder had been glued many times and so I ordered the part itself and replaced the entire assembly without rewiring the gaze sensors. Works fine but the image of the patient's eye on the monitor is no longer crisp. What needs to be calibrated? Dick Scholz

[DOCJDH]

What does calibration mean? I do not use the gaze tracking feature at all and the lens holder and arm are one piece. The cracked lens holder had been glued many times and so I ordered the part itself and replaced the entire assembly without rewiring the gaze sensors. Works fine but the image of the patient's eye on the monitor is no longer crisp. What needs to be calibrated? Dick Scholz

I think the calibration is done by the instrument itself before patient does VF. I ignore it. Just need eye centered and run the VF. You were smart to install unit as you did. Can't help you with blurry eye except check lenses for smudges. Camera optics became poor over time but good enough to monitor their eye.

Sorry can't help more.

[fjpod]

Ours broke too. Superglue is holding.

[Sivert.eyemd]

Sorry to resurrect an old thread, but I have 3d printed a plastic lens holder for the HVF.
It doesn't have the LEDs, so it doesn't do gaze monitoring.