This study found that gender differences exist in the relationships between CCTs and the focused and sustained attention. For females, the TOTAL and SCORE are significantly lower when CCT is 6500 K. For males, however, the TOTAL and SCORE showed no significant differences among the three CCT conditions. Gender difference also exists in the perceived clarity. Although males felt no significant differences in clarity among the three CCT conditions, females felt that the clarity under the 2700 K condition is significantly lower. This finding in gender differences may indicate that females are more likely than males to be affected by the CCT conditions with regard to their focused and sustained attention.