C. Composite Strain Score

Composite strain score is an average of four binary

indicators (0 or 100):

• Blink score: 100 when the present blink frequency is less than 60%

of the base

• PERCLOS score: 100 when more than 20%

• Squint score: 100 when the present eye height is below 85% of the base

• Dilation score: 100 when the pupil dilation is greater than 115% of the base

This system works well and does not require much computer usage.