Spectacles with 50% blue light blocked lenses and spectral transmittance curve.

a: Spectacles with 50% blue light blocked lenses. b: Spectral transmittance curve.</p

Functional visual acuity (VA) parameters with and without blue light blocked glasses.

<p>Functional visual acuity (VA) parameters with and without blue light blocked glasses.</p

Rayleigh scattering phenomenon.

<p>a. The red light passes through the skim milk in a glass. b. The blue light scatters and little of it passes through the skim milk in a glass.</p

Reducing Short-Wavelength Blue Light in Dry Eye Patients with Unstable Tear Film Improves Performance on Tests of Visual Acuity

<div><p>Purpose</p><p>To investigate whether suppression of blue light can improve visual function in patients with short tear break up time (BUT) dry eye (DE).</p><p>Methods</p><p>Twenty-two patients with short BUT DE (10 men, 12 women; mean age, 32.4 ± 6.4 years; age range, 23–43 years) and 18 healthy controls (10 men, 8 women; mean age, 30.1 ± 7.4 years; age range, 20–49 years) underwent functional visual acuity (VA) examinations with and without wearing eyeglasses with 50% blue light blocked lenses. The functional VA parameters were starting VA, functional VA, and visual maintenance ratio.</p><p>Results</p><p>The baseline mean values (logarithm of the minimum angle of resolution, logMAR) of functional VA and the visual maintenance ratio were significantly worse in the DE patients than in the controls (<i>P</i> < 0.05), while no significant difference was observed in the baseline starting VA (<i>P</i> > 0.05). The DE patients had significant improvement in mean functional VA and visual maintenance ratio while wearing the glasses (<i>P</i> < 0.05), while there were no significant changes with and without the glasses in the control group (<i>P</i> > 0.05),</p><p>Conclusions</p><p>Protecting the eyes from short-wavelength blue light may help to ameliorate visual impairment associated with tear instability in patients with DE. This finding represents a new concept, which is that the blue light exposure might be harmful to visual function in patients with short BUT DE.</p></div

Mechanism of the effect of the blue light blocked lens on visual function.

<p>Red and blue lines represent red and blue light, respectively. a. Unstable tear film without blue light blocked lens. The blue light is scattering. b. Unstable tear film with blue light blocked lens. The lens is blocking the blue light.</p

Characteristics.

<p>Characteristics.</p

Correlations between the distance-corrected near visual acuity (DCNVA) and amplitude of accommodation (AA), the distance-corrected near functional visual acuity (DCNFVA), and AA in each group.

<p>The vertical axis shows the VA and the horizontal axis shows the AA. Significant linear correlations are seen in both of the presbyopia group’s combinations, and the slope of the linear regression between the DCNFVA and AA is steeper than between the DCNVA and AA. D, diopters.</p

Characteristics of the Study Participants.

Characteristics of the Study Participants.</p

A representative printout of typical functional visual acuity (VA) testing.

<p>The blue line denotes the Landolt corrected VA. The red line shows the time-wise changes in the VA during testing. The green line denotes the mean logarithm of the minimum angle of resolution (logMAR) over 60 seconds, defined as the functional VA. The yellow dots show the number of correct responses; the blue triangles indicate spontaneous blinks.</p

The Functional Visual Acuity Measurement Device, the Kowa AS-28.

<p>The Functional Visual Acuity Measurement Device, the Kowa AS-28.</p