Daily Contact Lenses (30 pack)

Material Composition Assumptions

A typical 30-pack of daily contact lenses weighs approximately 83 grams including all packaging components. The individual contact lenses themselves represent the smallest portion by weight, with silicone hydrogel lenses comprising 65-75% of modern products and traditional hydrogel materials making up the remaining 25-35%. The packaging dominates the total weight and includes aluminum foil blister pack tops, polyethylene or polypropylene blister trays, and paper or cardboard outer cartons. Each lens weighs less than 0.1 grams, while the protective blister packaging and foil sealing materials contribute the majority of the product’s material footprint.

Manufacturing Geography

Contact lens production occurs primarily in Costa Rica and Puerto Rico, where major manufacturers have established facilities to serve global markets. Costa Rica’s electrical grid operates at approximately 145 gCO2e/kWh due to significant hydroelectric and renewable energy infrastructure. These locations were selected for their regulatory environments, skilled workforce availability, and strategic positioning for distribution to North American and European markets. The manufacturing process requires precise temperature and humidity controls for sterile production environments, making energy consumption a significant factor in the total carbon footprint.

Regional Variation

Manufacturing Region	Grid Intensity	Estimated CCI Score	Adjustment vs Default
Costa Rica (renewable)	145 gCO2e/kWh	42	Baseline
Puerto Rico (mixed)	680 gCO2e/kWh	49	+17%
Ireland (wind/gas)	285 gCO2e/kWh	45	+7%
China (coal-heavy)	555 gCO2e/kWh	53	+26%
Germany (renewable transition)	366 gCO2e/kWh	47	+12%

Provenance Override Guidance

1. Manufacturing facility energy consumption data with breakdown of renewable versus grid electricity usage, including any on-site solar or wind generation capacity.
2. Transportation mode and distance documentation from manufacturing site to final distribution point, including ocean freight, trucking, and air cargo specifications.
3. Material supplier certifications for plastic resin feedstock with country of origin and production method details for hydrogel and silicone hydrogel base materials.
4. Packaging weight optimization data showing actual aluminum foil thickness, blister tray dimensions, and carton material composition compared to industry standards.
5. Waste heat recovery systems documentation and energy efficiency measures implemented in sterile manufacturing cleanroom operations.

Methodology Notes

• The CCI score represents cradle-to-gate emissions for one 30-pack unit including all packaging materials but excluding end-of-life disposal impacts.
• Scope 3 dominates at 74% due to upstream plastic production from petrochemical feedstocks and complex packaging requirements for sterile medical devices.
• Scope 2 accounts for 18% reflecting energy-intensive cleanroom manufacturing processes with stringent temperature and humidity controls.
• The functional unit covers one month of bilateral daily lens wear assuming normal replacement schedule without accounting for partial usage or extended wear.
• Distribution emissions assume average global shipping distances but exclude final mile delivery to consumers or retail locations.
• Manufacturing yield losses and quality control rejection rates are included in the base calculation but may vary significantly between facilities.
• End-of-life impacts from improper disposal in wastewater systems are excluded from this cradle-to-gate assessment despite environmental significance.