The patient see the computer screen as trapeze

**george dimitrov** · 10-17-2008, 05:37 AM

Hallo,

I have a client who ordered CT Bifo with prescription Sph.+6.50 ADD2.50.
Now his complain is that the computer's screen looks like trapez...:hammer:. The bootom is wither than the top.
Have you met such case in your practice?!

**chip anderson** · 10-17-2008, 05:54 AM

Isn't that what aspheric lenses are supposed to correct?
Plus lenses make things bigger, the add has more plus so it makes things even bigger at the bottom. Plus lenses distort things more so on the edge hense the "trapeze". Aspheric lenses reduce this dramaticly.

Chip

Harry and Darryl to follow with a lot more detailed explaination and numbers but basicly the above is the problem.

**Uilleann** · 10-17-2008, 07:28 AM

Or just have him adjust the geometry of the screen with those little buttons on the bottom! nyuk!:hammer:

**dweinstein** · 10-17-2008, 08:21 AM

TRAPEZOID!!!!:hammer:

**Uncle Fester** · 10-17-2008, 08:21 AM

Must have been thinking "Trapezoid".

**Uncle Fester** · 10-17-2008, 08:36 AM

Originally Posted by george dimitrov

Hallo,

I have a client who ordered CT Bifo with prescription Sph.+6.50 ADD2.50.
Now his complain is that the computer's screen looks like trapez...:hammer:. The bootom is wither than the top.
Have you met such case in your practice?!

This could be due to the angle or wrap of the glasses or a base curve change.

**Framebender** · 10-17-2008, 09:04 AM

Give the guy a break . . . he probably speaks better English than you do Bulgarian!

:cheers:

**OpticianVlad** · 10-19-2008, 10:28 PM

Im not a contact lens expert. but it sounds like that's what you may be talking about. If it's regular bifocals, then add some pantoscopic tilt to reduce vertex distance at the seg..

good luck.

**i care guy** · 10-20-2008, 01:02 AM

I would check the PD , Panto and Base curve.
You could also increase the frame curvature.
Check for prism by dotting the OC in relation to the sag height. Also you could do that with frames on the lensometer.
Compare these findings with his previous pair.

**chip anderson** · 10-24-2008, 07:07 PM

One of my computer Guru's had this problem yesterday. Had just had Rx change, increase in add only, same frame, same lens type, same seg.ht, etc. Told him to try for a few days. Was back in the office today with same complaint. I adjusted nose pads only to move lenses a little further away and a scoatch higher. Problem went away.

Chip