Background Eyestrain is a serious quality of life problem, especially in the workplace. In particular, work at visual display terminals (VDTS) is a common cause, of eyestrain. Monoglucosyl rutin (MGR) is a highly water-soluble α-glucose adduct of rutin. Previous studies have demonstrated that rutin improved dry eye. Thus. we hypothesized that MGR could alleviate eyestrain caused by work at VDTs. In this clin. study, we evaluated whether MGR could improve cyestrain in healthy adults. Method This study was designed as a randomized, placebo-controlled, double-blind, crossover study. Twenty healthy Japanesc adults who tended to feel eyestrain were recruited to participate. During the first test period, the participants were asked to drink either a test food containing 352 mg of MGR or a placebo food without MGR. After the food intake, the participants did personal computer work at VDT for 30 min and then relaxed for 20 min. We evaluated the participants' eyestrain using an objective parameter (high-frequency component I, HFC I) and subjective parameters (visual analog scale). After 7 days, for the second test period, the participants consumed an alternate food following the same protocol as during the first test period. Results The objective parameter of cyestrain (HFCl) was significantly lower in the MGR group than that in the placebo group. The subjective parameters of eyestrain and waist stiffness were improved in the MGR group in comparison with those in the placebo group. Conclusion MGR supplementation has the effect to objectively and subjectively improve eyestrain symptoms due to VDT use.