Results 1 to 8 of 8

Thread: Mounting lens in a heated zyl frame

  1. #1
    OptiBoard Apprentice
    Join Date
    Feb 2005
    Location
    Denver
    Occupation
    Optometrist
    Posts
    26

    Mounting lens in a heated zyl frame

    If a zyl frame has to be heated until it's really rubbery and popping in the the lens makes the temples splay out significantly, would you say the lens should have been cut down more? Besides having to heat the bridge to get it back to fitting a regular head, is there any affect on a polycarbonate lens when it comes to distortion or power changes in the periphery?

  2. #2
    What's up? drk's Avatar
    Join Date
    Mar 2004
    Location
    Ohio
    Occupation
    Optometrist
    Posts
    9,388
    Maybe. If you can't true up the frame, the lens could be too big.

    Maybe on lens flexure, if the frame is too tight and the lens thin. Probably more of an issue with metal frames.

    You can make a polariscope with an LCD computer monitor wearing a pair of polarized sunglasses to see how much stress.

  3. #3
    Master OptiBoarder OptiBoard Silver Supporter Jubilee's Avatar
    Join Date
    May 2001
    Location
    United States
    Occupation
    Dispensing Optician
    Posts
    3,197
    Lens could be big, or sometimes I see this with mismatched frame and lens base curves. Lens 2 base, frame is 6 base. C-size is the same but due to the changes in the frame curves, temples end up splayed. Heat frame to adjust bridge and /or temples to wrangle them back in.
    "Some believe in destiny, and some believe in fate. But I believe that happiness is something we create."-Something More by Sugarland

  4. #4
    OptiBoardaholic OptiBoard Gold Supporter Mick's Avatar
    Join Date
    Jun 2010
    Location
    Cowtown,TEXAS
    Occupation
    Dispensing Optician
    Posts
    263
    If your frame is "rubbery" , maybe you are using too much heat. Try easing up and insert lenses as the frame shows a LITTLE flexibility. Should be much easier to maintain frame adjustment.

  5. #5
    Rochester Optical WFruit's Avatar
    Join Date
    Nov 2007
    Location
    Rochester, NY
    Occupation
    Optical Wholesale Lab (other positions)
    Posts
    1,273
    I've gotten to the point where I cold insert everything. If it needs to be heated, the lenses are too big.

    Also you can look at the eyewire rim. It should be perpendicular to the lens (more or less). When the lens is too big, it usually slants back (front is higher than the back) at a very noticeable angle.

    The temples being splayed out is almost always due to putting a flat base lens in a curved frame. What's the base curve of the lenses in question?
    There are rules. Knowing those are easy. There are exceptions to the rules. Knowing those are easy. Knowing when to use them is slightly less easy. There are exceptions to the exceptions. Knowing those is a little more tricky, and know when to use those is even more so. Our industry is FULL of all of the above.

  6. #6
    Master OptiBoarder TLG's Avatar
    Join Date
    Feb 2007
    Location
    S. California
    Occupation
    Dispensing Optician
    Posts
    814
    Some zyls have an annoyingly large block of zyl that the hinge is mounted onto that come right to the very edge of the of the lens, resting against the hide-a-bevel. The higher the minus, the more likely it will be pushing the temples out. What you have to do is hand edge the hide-a-bevel just slightly to move the edge of the lens off of the frame (be careful to not take much off or it can get ugly looking quick). If you still can't bend the endpiece in normally, remove the lens, heat the endpiece just enough to soften it and then bend the endpiece in without the lens in it; actually, bend it in a little too much and let it cool - then cold mount it. Now when it pushes the endpiece out on mounting it will line up properly. Takes some practice but I do it a lot and it works well.

  7. #7
    OptiBoard Apprentice
    Join Date
    Feb 2005
    Location
    Denver
    Occupation
    Optometrist
    Posts
    26
    Thanks for everyone's comments. I heated the bridge quite a bit and thought I might overdo it.

    I don't know what the BC was but I'm going to guess it was pretty low (aspheric -5.50 poly). As an aside, I'm just starting to edge and the lense pouches don't say what the base curves are. I could measure them.

  8. #8
    Master OptiBoarder OptiBoard Gold Supporter
    Join Date
    Mar 2012
    Location
    Maryland
    Occupation
    Dispensing Optician
    Posts
    2,103
    Be careful sizing those aspheric poly/1.67 lenses, you can get warped lenses/stress fractures in the center very very easily, especially if you are not cold glazing them. Especially in the winter, you heat the frame, jam the lens in there, patient goes and runs errands for 3 months in the freezing cold, frame shrinks. Problems.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Mounting a Silhouette 7395/7799 rimless frame
    By adam86 in forum General Optics and Eyecare Discussion Forum
    Replies: 3
    Last Post: 06-09-2014, 10:49 AM
  2. Need a Lens Case/Trial Lens Frame?
    By kelamach in forum Optical Marketplace
    Replies: 3
    Last Post: 10-22-2012, 03:13 PM
  3. Replies: 0
    Last Post: 03-24-2010, 06:51 PM
  4. What lens material is recommended for groove mounting in a full-rim frame?
    By dave191 in forum General Optics and Eyecare Discussion Forum
    Replies: 51
    Last Post: 09-20-2005, 08:14 AM
  5. Let's have a heated debate!
    By Maria in forum Just Conversation
    Replies: 64
    Last Post: 03-04-2002, 08:46 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •