What causes/corrections exist for distorted shapes seen with progressive lenses?!
Question: What causes/corrections exist for distorted shapes seen with progressive lenses?
1.) My depth of near-field changed, making driving my car feel like driving a much higher up SUV (I was shocked when my foot reached the ground so quickly upon stepping out).
2.) My range of clear vision seems much narrower, in that I am actually noticing it. I need to turn my head more than before to read across a page.
3.) My rectangular laptop screen now appears to be a trapezoid (narrower at the top and wider at the bottom).
The last of these three is my biggest concern, as the sensation of this misshapen rectangle is strong enough to be very very distracting. In discussion with the optician who fitted these, she suggests "pantoscopic tilt" is the solution. After much reading, I believe I understand this concept, as (in simplistic terms) we try to get the optical axis of the image in line with the rotational center of the eye as well as the proper area of the lens needed to focus for that distance. Simple experimenting with changing the tilt angle and/or height of the lens above the bridge of my nose are easy with these frames (spring-loaded arms easily go outside my ears, and pushing the glasses forward down the bridge of my nose changes the height, albeit also the vertex distance). In this case, I am only looking to see if any of this has an effect on making the trapezoid shape look more like the rectange it is, as that would suggest that pantoscopic tilt was the correct solution. However, nothing I do shows any real change in the shape of my laptop screen.
I never noticed this effect with my old lenses, and I don't want to live with this unless I have no choice. Given the simple problem of a back-lit rectangle (my laptop screen) looking like a trapezoid from a distance of about 18-24 inches, is pantoscopic tilt the correct direction, or has something else been missed?
This will all be worked out with my otherwise very pleasant and professional (non-chain) optician, but there are such great experience represented here I am hoping someone will recognize this symptom and suggest a direction. Thank you.
Answers:
Best Answer - Chosen by Voters
You should probably ask some questions about the brand of progressive used. If you purchased all of your progressives the same place, they can tell this from your records. Even if you didn't, this information can be obtained by looking at some nearly invisible marking on your lenses. Progressives are constantly evolving to eliminate the effects you are complaining about. However twenty year old designs are still on the market. My bet is the poorly performing progressives are an older design. Hopefully you at least got them at a bargain price.
optometrist
You aren't getting the real effect of what the pantscopic tilt can change though by pushing them farther down your nose at the same time.The pantoscopic tilt should be bringing the bottom of the lenses in closer to your eyes.
But, at the same time, if after pushing them down farther on your nose and looking just through the very top of the lenses , the trapezoid is still there, it eliminates the chance that the progression is starting too high , which seemed like the typical cause for your first symptom.
If the trapezoid is still there, even through the very top of your lenses , it suggests to me that the axis is incorrect.
Optician