Background:The new generation of intraocular lenses(IOL)with an additional blue light filter has a slight yellowish colour(compared to the IOLs with only a UV filter)due to its different light transmitting properties.This could have an effect on contrast sensitivity and subjective visual perception.Patients and Methods:In this intraindividual prospective comparative study including 14 cataract patients without further ocular pathology,a blue light filtering IOL(SN60AT,Alcon)was implanted in one eye and 1 month later a conventional single-piece IOL(SA60AT,Alcon)was fitted into the fellow eye.The visual acuity and the clinical findings were assessed at one day and four weeks post-operatively.Contrast sensitivity was tested under defined mesopic(6cd/m2)and high mesopic(18,8cd/m2)light conditions in the Ginsburg Box using the Functional Acuity Contrast Test(F.A.C.T.).Furthermore,subjective differences in the visual perception of both eyes were noted.Results:The contrast sensitivity testing 1 day and 1 month postoperatively,revealed no statistically significant differences(P > 0008)between both IOL types for all spatial frequencies(1,5/3/6/12/18 cpd)and light levels.13 patients(85%)reported no differences in the colour perception of both eyes,and none had visual disturbances.Conclusion:This intraindividual comparison revealed no relevant differences concerning mesopic contrast sensitivity and the subjective visual perception after implantation of one IOL with or without a blue light filter. Background: The new generation of intraocular lenses (IOL) with an additional blue light filter has a slight yellowish color (compared to the IOLs with only a UV filter) due to its different light transmitting properties. This could have an effect on contrast sensitivity and subjective visual perception. Patients and Methods: In this intraindividual prospective comparative study 14 Cataract patients without further ocular pathology, a blue light filtering IOL (SN60AT, Alcon) was implanted in one eye and 1 month later a conventional single-piece IOL (SA60AT , Alcon) was fitted into the fellow eye. The visual acuity and the clinical findings were assessed at one day and four weeks post-operatively. Contrast sensitivity was tested under defined mesopic (6 cd / m2) and high mesopic (18,8 cd / m2 ) light conditions in the Ginsburg Box using the Functional Acuity Contrast Test (FACT) .Furthermore, subjective differences in the visual perception of both eyes were observed. Results: The contrast sensitivity testing 1 day and 1 month postoperatively, revealed no statistically significant differences (P> 0008) between both IOL types for all spatial frequencies (1,5 / 3/6/12/18 cpd) and light levels.13 patients (85% ) reported no differences in the color perception of both eyes, and none had visual disturbances. Confclusion: This intraindividual comparison revealed no relevant differences concerning mesopic contrast sensitivity and the subjective visual perception after implantation of one IOL with or without a blue light filter.