| # | Country | Total Patents | |
|---|---|---|---|
| #1 | United States | 8 | |
| #2 | Canada | 3 | |
| #3 | France | 1 | |
| #4 | United Kingdom | 1 |
| # | Industry | |
|---|---|---|
| #1 | Optics | |
| #2 | Medical technology | |
| #3 | Machine tools | |
| #4 | Machines |
| # | Technology | |
|---|---|---|
| #1 | Spectacles | |
| #2 | Diagnosis and surgery | |
| #3 | Grinding or polishing devices | |
| #4 | Manufacturing processes |
| # | Name | Total Patents |
|---|---|---|
| #1 | Clement George A | 7 |
| #2 | Hans Clement | 4 |
| #3 | Dey Gilbert S | 2 |
| #4 | Opitz Gustav W | 1 |
| #5 | Otto Wittel | 1 |
| Publication | Filing date | Title |
|---|---|---|
| US1701258A | Ophthalmological apparatus | |
| GB221415A | Improvements in bifocal lenses | |
| US1625075A | Ophthalmological apparatus | |
| US1494889A | Bifocal-lens blank | |
| US1467307A | Lens-blocking mechanism | |
| US1467308A | Method of grinding one-piece bifocal lenses | |
| US1401238A | Multifocal lens | |
| US1406798A | Lens-cutting machine | |
| US1172827A | Ophthalmoscope. | |
| CA479505A | Apparatus for grinding lenses | |
| CA479506A | Apparatus for grinding lenses | |
| CA240636A | Bifocal lense |