Background: Dry eye is a very common yet often mis-diagnosed ocular disorder. The stability of the tear film plays an important role in the integrity of ocular surface. Fluorescein Tear Breakup Time FBUT is the most frequently used diagnostic test to determine tear film instability. There is still a debate about whether age and gender affect tear film stability. Objective: To study the effect of age and gender on Tear Film Breakup Time. Patients and Methods: The study was performed on 100 random individuals (200 eyes) older than 18 years old. Full history taking and thorough slit lamp examination were performed first, followed by FBUT. The results were recorded and analyzed. Results: The study showed that there was negative relation between age and FBUT with high significance (p < 0.001). The study also showed that there was high statistically significance difference (p < 0.001) between male and female as regard FBUT, and that the values of FBUT were higher in males than in females. Conclusion: Tear film becomes less stable with age, possibly due to significant changes in the tear lipid layer leading to less protection from evaporation in the aging population. The observed changes are more marked in women than in men.