The aim of the article is to estimate the intravitreal half-lives of ranibizumab and aflibercept (VEGF Trap-eye; VTE) in human eyes.Using a published mathematical model for rabbits, the intravitreal half-lives of ranibizumab and bevacizumab were calculated and compared to empirical data.The slope coefficient within the model was changed to set the bevacizumab output equal to experimental values to meet 3 goals: firstly, to validate the model in rabbit eyes; secondly, to test the mutability of the model to monkey eyes; thirdly, to calculate the half-lives of ranibizumab and the VTE in human eyes.The half-life calculations for ranibizumab deviate from published rabbit and monkey values by only 8.3% and 4.2%.Using the experimentally determined half-life of bevacizumab in human eyes (8.25 days) to set the equation, the half-lives of ranibizumab and the VTE are calculated to be 4.75 days and 7.13 days in human eyes.The intraocular half-lives of ranibizumab and the VTE are estimated using existing published animal and human data and a mathematical model.The validity of these half-lives and binding activities, however, awaits clinical correlation.