Pigmented contact lenses for managing ocular disorders

Area of Science:

• Biomaterials Science
• Ophthalmic Optics
• Photochemistry

Background:

• Ultraviolet (UV) radiation damages the retina, necessitating protective eyewear.
• Near-visible light also poses risks, but is often unfiltered by commercial lenses.
• Light filtering benefits patients with migraines, amblyopia, and color blindness.

Purpose of the Study:

• To explore the incorporation of natural agro-product pigments into contact lenses.
• To develop contact lenses capable of blocking specific light spectrum ranges.
• To assess the protective and therapeutic potential of these novel pigmented lenses.

Main Methods:

• Extraction of pigments from turmeric, spinach, paprika, and woad powders using ethanol.
• Incorporation of pigments into p-HEMA and silicone hydrogel contact lenses via immersion.
• Characterization using absorptivity, transmittance measurements, and degradation studies.

Main Results:

• Turmeric-pigmented lenses (silicone hydrogels) function as Class 1 UV blockers, blocking >95% of UVR while retaining >90% visible light transparency.
• Spinach, paprika, and woad pigmented lenses selectively mitigate >20% visible light transmission.
• Pigment incorporation prevented scattering, opacity, and leaching, demonstrating good stability.

Conclusions:

• Natural food pigments can be effectively incorporated into contact lenses for light filtering.
• These pigmented lenses offer UV protection and selective visible light management.
• Potential applications include enhanced eye protection and therapeutic interventions for visual disorders.