Large-scale integration in tablet screens for blue-light reduction with optimized color: The effects on sleep, sleepiness, and ocular parameters

Figures & data

Figure 1. The spectral component of white light emitted from the display of the IROMI® Tablet device with (dotted line) and without large-scale integration for blue-light control (solid line). Blue-light reduction rate is 20.1% (@ 434 nm).

Figure 2. Screen images from the tablet device with and without large-scale integration (LSI) for blue-light control. (a) Original screen image without LSI for blue-light control; (b) Screen image with LSI for blue-light reduction only; (c) Screen image with LSI for blue-light reduction and color control. Note the display is yellowish with blue-light reduction only whereas the image is acceptable with color control by LSI.

Figure 3. The ocular parameters of functional visual acuity (left panel), maximum blinking interval (center panel), and number of dry eye symptoms (right panel) are shown for participants while they performed tasks for two hours, from 22:00 to 24:00, on self-luminous devices with large-scale integration (LSI) for blue-light reduction and without LSI (control).

Notes: *p < 0.05; n = 30, two-tail paired t test.

Table 1. Visual quality^a with and without large-scale integration for blue-light reduction

	Without LSI	With LSI	p-value^b
Clarity	3.39 ± 1.12	4.42 ± 1.04	0.500
Sharpness	3.86 ± 0.83	3.64 ± 0.93	0.102
Less fatigue	2.53 ± 1.34	3.00 ± 1.32	0.048
Hue	3.50 ± 1.45	3.29 ± 1.21	0.055

Notes: LSI, large-scale integration for blue-light reduction.

Values are mean ± standard deviation for 30 adults.

^a Each element of visual quality was assessed on a visual analog scale from 5 (best) to 1 (worst) compared with their own portable device.

^b Two-tail paired t test.

Figure 4. The increase in sleepiness of participants (n = 30) measured by the Karolinska Sleepiness Scale at bedtime (24:00) after a two-hour task at night. The increase in sleepiness tended to be greater with large-scale integration (LSI) for blue-light reduction than without LSI (control).