Complicated RX
High Plus
High-plus prescriptions ask a lot of a frame and a lens. Frame shape, decentration, and curvature all affect how the finished pair performs on your patient's face, from optical clarity through the whole field of view to how comfortably they adapt to the new lens design. Below, we share our recommendations for selecting a frame, fitting monocular patients, and choosing the lens shape, standard or lenticularized, that gives your patient the best combination of optics and comfort.
Frame Selection Tips
Getting the Fit Right
It is crucial to have the proper care when selecting a frame with a high plus lens. These are the three guidelines we recommend following when selecting your frame.
Minimizing decentration is important with high plus RX's.
Too much decentration causes unnecessary nasal thickness, and it serves no purpose.
On this type of RX, a very narrow frame accentuates the thickness at the top and bottom of the frame.
The corners create an area with drastic thickness changes on the finished glasses, making the lenses look thicker. An oval or round shape is preferable.
If your patient only has one good eye, you might want to consider putting the lens on center (disregard the PD). Often, the compromise in optics is minuscule compared to the aesthetic benefit.
We can make some beautiful high-plus lenses using the shapes outlined below. To do this, we change the lens curves through a process called freeform lenticularization.
It is important to keep in mind that some patients are very sensitive to these changes in curvature. If you have a patient who you feel would be sensitive to these changes, we wouldn't recommend straying from their current eyeglass lens design.
The Shapes
Standard
Shape #10
Standard
Processed much like a traditional myodisc, but with an additional finishing process to blend the bowl to the rest of the lens.
Shape #11
Lenticular
Used when the RX exceeds machine limitations on Shape 4. A concave curve is cut into the front of the lens to make a lens with more power.
The Shapes
Lenticularized
Shape #12
HD Supermodular
Used when the RX exceeds machine limitations on Shape 4. A concave curve is cut into the front of the lens to make a lens with more power.
Shape #13
Backside Supermodular
Used to further thin a Shape 5 lens. The lens is run through the blending process on both the front and the back of the lens.
Shape #14
Backside Supermodular
Processed much like a traditional myodisc, but with an additional finishing process to blend the bowl to the rest of the lens.
Shape #15
Aspheric Wrap
Used when the RX exceeds machine limitations on Shape 4. A concave curve is cut into the front of the lens to make a lens with more power.