Reduced carbon footprint in contact lenses manufacturing and their packaging

Authors
1^st /Presenting Author: Aldo Zucaro 
Co-Authors: Paul Riggs, Richard Farwell
 

Purpose 
Previous work has identified ways to help reduce carbonemissions from polypropylene used in contact lens blister packs (Zucaro, BCLA conference, 2023). This work evaluated carbon emissions across the production of contact lenses – including materials, energy and packaging – to ascertain further opportunities for carbon footprint reduction. 
 

Methods
An assessment of greenhouse gas (GHG) emissions, using 2022 emissions data, determined that producing contact lenses generates an average of 72g CO₂e (carbon dioxide equivalence) per lens (including Scope 1 and Scope 2 direct and indirect emissions, as well as Scope 3.1 Purchased Goods and Services). The assessment focused on the primary materials (polypropylene, aluminium, and silicone hydrogel) used in contact lens production across all lens types/modalities and across all manufacturing facilities. A cradle-to-gate approach was applied, comparing traditional methods with renewable and/or certified lower-carbon alternatives, using supplier data validated through established carbon accounting methodologies.
 

Results
There were significant carbon reductions across key material and operational areas with reduction of grams CO₂e /lens for plastic manufacturing, aluminium manufacturing, silicone hydrogel manufacturing, renewable energy in operations and sustainable secondary packaging being  2,  1.8, 0.7 , 12.7  and 0.5 respectively. 

Together, these achieve a total average reduction of 17.7 grams CO₂e per lens, representing an estimated 24.6% decrease in carbon emissions compared to baseline.
 

Conclusion
This analysis demonstrates that integrating renewable and lower-carbon materials, alongside renewable energy in operations, could reduce the carbon footprint of contact lenses manufacturing and their packaging by nearly 25%. These results underscore the transformative potential of lower-carbon material selection, sustainable operational processes, and supplier collaboration in advancing environmental goals without compromising the functional integrity of contact lens products.