Ophthalmic Lens Selective Blue Light Filtering
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Solution Overview
Problem
Existing ophthalmological lenses for sunglasses do not adequately balance protection against harmful blue light with the preservation of visual perception and contrast, leading to visual fatigue and safety concerns, particularly for drivers.
Innovation Solution
The development of an ophthalmological lens with a specific transmission spectrum that attenuates harmful blue light while maintaining high transmission in the blue-violet range, enhancing contrast perception by selectively filtering wavelengths between 450nm and 500nm and between 570nm and 595nm.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If ophthalmic lenses use pronounced filters in the visible blue part of the spectrum (400nm-480nm) to block harmful blue light, then protection against age-related macular degeneration is improved, but transmission of good blue light (450nm-480nm) is significantly attenuated, impairing visual spectral perception
Solution Approach 1:
The patent divides the blue light spectrum into two distinct segments: harmful blue light (426nm-440nm) and good blue light (450nm-480nm). By applying selective filtering only to the harmful segment while preserving the good segment, the lens achieves protection against AMD without impairing visual spectral perception. This segmentation resolves the contradiction by targeting only the specific wavelength range that causes damage.
Solution Approach 2:
The lens applies different optical properties to different wavelength regions. Specifically, it creates a localized filter effect at 426nm-440nm (first transmission minimum with transmission ≤10%) while maintaining high transmission (>10%) in the 450nm-500nm range. This local quality approach ensures that protection is applied precisely where needed without affecting beneficial wavelengths.
2Object-affected harmful factors
If ophthalmic lenses filter blue light wavelengths to protect against harmful radiation, then protection against retinal damage is improved, but contrast perception is altered, causing visual fatigue and safety concerns
Solution Approach 1:
The patent segments the filtering action to affect only the specific harmful wavelength range (426nm-440nm) while preserving the broader blue spectrum (450nm-500nm) that contributes to contrast perception. This selective segmentation maintains visual reliability by keeping the good blue light that enhances contrast while removing only the harmful portion.
Solution Approach 2:
The patent carefully controls the transmission parameter at the first minimum (426nm-440nm) to be less than or equal to 10%, which is sufficient to block harmful radiation but not so restrictive as to degrade contrast perception. This parameter optimization resolves the contradiction by finding the precise threshold that provides protection without compromising visual safety.
3Object-affected harmful factors
If ophthalmic lenses block all radiation below 400nm to prevent UV damage, then protection against corneal and retinal injury is improved, but transmission of beneficial violet and blue light is reduced, affecting color perception
Solution Approach 1:
The patent segments the ultraviolet and visible spectrum boundaries, maintaining strong blocking below 380nm (transmission <1%) for UV protection while creating a transmission maximum in the 390nm-420nm range (transmission >8%). This segmentation allows beneficial violet light to pass through while still providing comprehensive UV protection.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The lens effectively blocks harmful blue light, reducing the risk of age-related macular degeneration while improving color perception and contrast, thereby enhancing user safety in bright conditions.
Implementation Method 1
at least one of the substrates comprising one or more dyes and/or pigments, said dyes and/or pigments of all the substrates cooperating together in order to absorb the light passing through the lens
Data Source
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AI summary
The invention relates to an ophthalmic lens (1) for a pair of sunglasses, said ophthalmic lens including at least one substrate (13), the lens (1) having a transmission spectrum such that: • the transmittance at wavelengths shorter than 380 nm is lower than 1% • the spectrum includes a first transmittance maximum (MAX-1) having a transmittance higher than 8% between 390 nm and 420 nm • the spectrum includes a first transmittance minimum (MIN-1) between 426 nm and 440 nm • the transmittance between 450 nm and 500 nm is higher than 10% • the spectrum includes between 570 nm and 595 nm a second transmittance minimum (MIN-2) • the spectrum includes between 590 nm and 620 nm a second transmittance maximum (MAX-2) • the spectrum includes in the wavelength range comprised between 620 nm and 640 nm a third transmittance minimum (MIN-3) • the transmittance at wavelengths longer than 640 nm is higher than 14%.