Journal of Applied Sciences1812-56541812-5662Asian Network for Scientific Information10.3923/jas.2008.68.76BatmazIhsan OzturkMustafa 1200881In this study, it is aimed to evaluate the mental workload by using a practical way which based on measuring pupil diameter changes that occurs under mental processing. To determine the mental effort required for each task, the video record of subjects` eyes are taken while they are performed different tasks and pupils were measured from the records. A group of university student, one female 9 males participated to the experiment. Additionally, NASA-TLX questionnaire is applied for the related mental tasks. For verification of results obtained from both indices, the correlation coefficient is calculated task base. The results show that there is weak and negative correlation between the indices on task base except 3rd task. By investigating pupil diameter measurements data too, it is founded that pupil dilates under mental workload during performing related tasks. For all tasks, pupil diameters of response periods increased according to reference baseline period.]]>Aboyoun, D.C. and M.J. Dabbs,199826415420Baldwin, C.L.,20034132141Beatty, J.,198291276292Bryan, B.A. and B.P. Stone,20037485504Hess, E.H. and J.M. Polt,1960132349350Hess, E.H.,19652124654Kahneman, D.,1973Kaptan, S.,1993pp: 231-252pp: 231-252Karaka, S. and E. Basar,20032003Luximon, A. and R.S. Goonetilleke,200144229243De La Teja, G.M.M.,200127411415Miyake, S.,200140233238Moray, N.,19882123150Morgan, C.T.,19801980Noyes, J., K. Garland and L. Ribbons,200435111113Özesmi, Ç., C. Süer, A. Gölgeli, M. A ç o lu, N. Dolu and A. Y lmaz,20002000Stern, J.A.,19971997Vitense, H.S., J.A. Jacko and V.K. Emery,2003466887Young, M.S. and N.A. Stanton,20024510181020