Average Co-Inventor Count = 2.18
ph-index = 4
The patent ph-index is calculated by counting the number of publications for which an author has been cited by other authors at least that same number of times.
Company Filing History:
1. Pilkington Barnes Hind, Inc. (2 from 13 patents)
2. Other (1 from 832,912 patents)
3. Wesley-Jessen Corporation (1 from 43 patents)
4 patents:
1. 5980040 - Pinhole lens and contact lens
2. 5786883 - Annular mask contact lenses
3. 5757458 - Annular mask contact lenses
4. 5245367 - Annular mask contact lenses