Extended Range of Cylinder lenses or extended range of Sphere lenses. 20 April 2014

[Energy Conservation in Housing]

3 June 2010

Extended Range of Cylinder lenses or extended range of Sphere lenses.

As you know, the Reichert phoroptor has up to 6.00 D of cylinder power.

By using the 2D plug-in cyl lenses, that extends the range to 8 D.

In the past year, I had requests from two of our ODs for more cylinder power.

I have equipped two clinics with a pair of -5.00 D plug-in cylinder lenses. That extends the phoroptor range up to 11.00 D of cylinder.

Making these plug in –5.00 D cylinder lenses is a long, slow process, as the lenses have to be custom ordered, and eventually glued into an existing plug-in lens frame, on axis.

(The way I make the –5.00 D plug in lenses, is the following:

The internal cylinder lenses of the phoroptor are the same diameter (lens size) as the plug in cylinder lens. I order a –5.00 D cylinder replacement lens. I use the metal frame from the -0.12 cylinder plug in lens. I dissolve the glue holding the lens in place. Then I glue in the –5.00 D lens, on axis, then attach a –5.00 D label to the outside of the frame.

When you plug in the lens, it starts you at –5.00 D, and you can then add more power in 0.25 D increments, up to 11.00 D)

Extended SPHERE range for the Phoroptor (20 April 2014)

I recently got a suggestions from another optometrist, that an EASY way to extend the range of the Reichert phoroptor beyond the –19.00 D sphere limit, is to remove the face shield, and clip a trial lens to the clip that usually holds the face shield.

By clipping on a –6.00 sphere, that extends the range of the phoroptor to –25.00

I tried this very thing with lenses from the Topcon trial lens set that many exam rooms (at Kaiser, in the Washington DC area) are equipped with. Such a trial lens is easily held in place by the clip.

In a similar fashion, the phoroptor can have an extended sphere range. By buying a pair of –6.00 D spheres, and gluing them in the 0.12 cylinder frame, that can extend the phoroptor beyond the usual –19.00 D. sphere limit. By refracting using the –6.00 D spheres, due to the vertex distance, the plug-in sphere lenses add another –5.50 D to the range of the phoroptor.

This plug-in sphere then extends the phoroptor sphere range from –19.00 D to –24.50 D.

To be safe, the phoroptor refraction should be trial-framed, to determine the final sphere power.

Item Description: Reichert 11625 Internal Lens –6.00 (Sphere)

Lombart Part number: RE9RE11624622

Price of lens, as of July 2013: $63.75

(The internal sphere lenses of the phoroptor have the same 20 mm diameter as the 0.12 cylinder frame).

[Energy Conservation in Housing]

12 October 2018.

Today I was re-gluing a pair of -2.00 plug in auxiliary cylinders.  (The lenses had eventually fallen out of the frame, due to aged or insufficient glue, done by Reichert.)

I was showing an optician how tough it was to mark up the axis, prior to re-gluing the lens.  The -2.00 cylinder lens is about 20 mm wide, and the marking prongs on the lensometer are nearly 20 mm apart.  So, I have to move the cylinder lens to one edge of the lensometer, in an attempt to get the axis position dotted by the center prong and one of the side prongs.  It is really tough to hold the lens in position, AND to get 2 of the prongs to mark the lens.  I then draw my best axis line through the two ink dots.  Because this (de-centered method of) marking is so unstable, I try to mark the axis 2 to 4 times, and use the best guess of the axis position.

Anyway, the optician suggested I tape the lens to a larger lens (or other transparent surface), so it is easier to hold, and then I could mark the axis with all 3 prongs of the lens marking device.  And then she provided me with a plano blank lens.  (I then taped the cylinder lens to the concave side of the lens blank.)

That suggestion made the marking process much more stable.  Two of the prong marks were on the lens blank, and one on the -2.00 cylinder lens.  All I had to do was draw a line across the cylinder lens, as it lined up with the 3 dots of ink.  I repeated the process with two more axis lines, just to convince myself I had found a reliable axis line.

Another suitable material could be a flat piece of plexiglass, cut to a suitable size.  Just tape the cylinder lens to the plexiglass, and put it in the lensometer.