Difference between revisions of Guide:Reducing lens complexity
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(→How to reduce lens complexity: Added a reduction type column to the example table.) |
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|+ Example Spherical Reduction Schedule | |+ Example Spherical Reduction Schedule | ||
|- | |- | ||
! style="text-align:left;" | Reduction Type | |||
! colspan="2" | Normalized | ! colspan="2" | Normalized | ||
! colspan="2" | Differentials | ! colspan="2" | Differentials | ||
! style="text-align:left;" | Explanation | ! style="text-align:left;" | Explanation | ||
|- | |- | ||
| style="text-align:left;" | | |||
| Left | | Left | ||
| Right | | Right | ||
| Line 42: | Line 44: | ||
| style="text-align:left;" | | | style="text-align:left;" | | ||
|- | |- | ||
| rowspan="2" style="text-align:left;" | | |||
| -3.50 | | -3.50 | ||
| -4.00 | | -4.00 | ||
| Line 51: | Line 54: | ||
| | | | ||
|- | |- | ||
| rowspan="4" | Simple | |||
| -3.25 | | -3.25 | ||
| -3.75 | | -3.75 | ||
| | | | ||
| | | | ||
| style="text-align:left;" | | | style="text-align:left;" | perform normalized reduction | ||
|- style="text-align:left;" | |- style="text-align:left;" | ||
| colspan="4" style="text-align:center;" | wait 4 - 8 weeks | | colspan="4" style="text-align:center;" | wait 4 - 8 weeks | ||
| rule 4 | | (rule 4) | ||
|- | |- | ||
| | | | ||
| Line 64: | Line 68: | ||
| -2.00 | | -2.00 | ||
| -2.50 | | -2.50 | ||
| style="text-align:left;" | | | style="text-align:left;" | perform differential reduction | ||
|- style="text-align:left;" | |- style="text-align:left;" | ||
| colspan="4" style="text-align:center;" | wait 4 - 8 weeks | | colspan="4" style="text-align:center;" | wait 4 - 8 weeks | ||
| | | | ||
|- style="font-weight:bold;" | |- style="font-weight:bold;" | ||
| rowspan="2" | Equalizing | |||
| -3.25 | | -3.25 | ||
| -3.50 | | -3.50 | ||
| -2.00 | | -2.00 | ||
| -2.25 | | -2.25 | ||
| style="text-align:left;" | | | style="text-align:left;" | both norms and diffs are reduced simultaneously (rule 3) | ||
|- style="text-align:left;" | |- style="text-align:left;" | ||
| colspan="4" style="text-align:center;" | wait 8 - 16 weeks | | colspan="4" style="text-align:center; font-weight:bold;" | wait 8 - 16 weeks | ||
| | | | ||
|- | |- | ||
| rowspan="4" | Simple | |||
| -3.00 | | -3.00 | ||
| -3.25 | | -3.25 | ||
| | | | ||
| | | | ||
| style="text-align:left;" | | | style="text-align:left;" | perform normalized reduction | ||
|- style="text-align:left;" | |- style="text-align:left;" | ||
| colspan="4" style="text-align:center;" | wait 4 - 8 weeks | | colspan="4" style="text-align:center;" | wait 4 - 8 weeks | ||
| rule 4 | | (rule 4) | ||
|- | |- | ||
| | | | ||
| Line 91: | Line 97: | ||
| -1.75 | | -1.75 | ||
| -2.00 | | -2.00 | ||
| style="text-align:left;" | | | style="text-align:left;" | perform differential reduction | ||
|- style="text-align:left;" | |- style="text-align:left;" | ||
| colspan="4" style="text-align:center;" | wait 4 - 8 weeks | | colspan="4" style="text-align:center;" | wait 4 - 8 weeks | ||
| | | | ||
|- style="font-weight:bold;" | |- style="font-weight:bold;" | ||
| rowspan="2" | Equalizing | |||
| -3.00 | | -3.00 | ||
| -3.00 | | -3.00 | ||
| -1.75 | | -1.75 | ||
| -1.75 | | -1.75 | ||
| style="text-align:left;" | | | style="text-align:left;" | both norms and diffs are reduced simultaneously (rule 3) | ||
|- style="text-align:left;" | |- style="text-align:left;" | ||
| colspan="4" style="text-align:center;" | wait 8 - 16 weeks | | colspan="4" style="text-align:center; font-weight:bold;" | wait 8 - 16 weeks | ||
| | | | ||
|} | |} | ||
Revision as of 17:12, 16 June 2020
 | This article is under construction. Please help develop it, whatever your level of expertise |
TODO: this article needs to be expanded for edge cases like already low diopters.
When to reduce lens complexity
Lens complexity is best reduced before getting into the low diopters range. Ideally, both eyes would be equal before -1.5 diopters. (TODO: cite an EM source for this)
How to reduce lens complexity
Make your first reduction a simple spherical reduction. This will teach you the basics of the EndMyopia methods.
There are two types of reductions:
- A simple reduction is a 0.25 diopter drop in lense power for both eyes, simultaneously
- An equalizing reduction is a 0.25 diopter drop in lense power for one eye, the eye with greater correction (more negative)
An equalizing reduction is done to bring the eyes closer to having the same level of correction.
Either type of reduction can be applied to spherical power or cylindrical power.
There are four rules for reducing complexity:
- Alternate types of reductions. Simple > Equalizing > Simple > Equalizing...
- Change only spherical or only cylindrical and never both simultaneously.
- For an equalizing reduction, change both differential lenses and normalized lenses simultaneously to keep the focal planes in sync.
- For a simple reduction, change differential lenses a few weeks after normalized lenses to keep changes to focal planes to a minimum.
A note on rule 3 and rule 4: Keeping focal planes in sync is a higher priority than keeping changes to focal planes to a minimum, thus rule 3 exists.
| Reduction Type | Normalized | Differentials | Explanation | ||
|---|---|---|---|---|---|
| Left | Right | Left | Right | ||
| -3.50 | -4.00 | -2.25 | -2.75 | Starting point | |
| wait 8 - 16 weeks | |||||
| Simple | -3.25 | -3.75 | perform normalized reduction | ||
| wait 4 - 8 weeks | (rule 4) | ||||
| -2.00 | -2.50 | perform differential reduction | |||
| wait 4 - 8 weeks | |||||
| Equalizing | -3.25 | -3.50 | -2.00 | -2.25 | both norms and diffs are reduced simultaneously (rule 3) |
| wait 8 - 16 weeks | |||||
| Simple | -3.00 | -3.25 | perform normalized reduction | ||
| wait 4 - 8 weeks | (rule 4) | ||||
| -1.75 | -2.00 | perform differential reduction | |||
| wait 4 - 8 weeks | |||||
| Equalizing | -3.00 | -3.00 | -1.75 | -1.75 | both norms and diffs are reduced simultaneously (rule 3) |
| wait 8 - 16 weeks | |||||