Does blue-violet filtering in contact lenses improve contrast sensitivity?

Area of Science:

• Ophthalmology
• Optometry
• Vision Science

Background:

• Contact lenses (CLs) are widely used for vision correction.
• Blue-violet filtering (BVF) technology in CLs aims to mitigate potential negative effects of blue light.
• The impact of BVF CLs on photopic contrast sensitivity (CS) requires further investigation.

Purpose of the Study:

• To compare photopic contrast sensitivity (CS) in healthy subjects using blue-violet filtering (BVF) contact lenses (CLs) versus clear CLs.
• To determine if variations in CS with BVF CLs depend on an individual's baseline CS measured with clear CLs.

Main Methods:

• Photopic CS was measured in 41 healthy adults using a digital optotype system at various spatial frequencies.
• Subjects were tested with both clear CLs and BVF CLs.
• Optical transmittance of both types of CLs was measured using a spectrophotometer.

Main Results:

• BVF CLs showed an absorption band with minimum transmittance at 428 nm.
• No significant CS differences were found between younger and older adults for either CL type.
• The change in CS with BVF CLs correlated significantly with baseline CS, indicating a personalized effect.

Conclusions:

• BVF CLs can enhance CS in individuals with lower baseline sensitivity but may reduce it in those with higher baseline sensitivity.
• The influence of BVF CLs on CS is a balance between reduced intraocular scattering (beneficial) and decreased light intensity (detrimental).
• Ophthalmologists and optometrists should consider individual CS when prescribing BVF CLs.