***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: PURPOSE To compare contrast acuity at different illumination levels and color vision and the subjective impression in patients after bilateral cataract surgery with a mixed implantation of a blue-light-filtering and an ultraviolet (UV)-filtering intraocular lens ( IOL ) .  DESIGN R and omized , controlled , double-masked , and bilateral study with intraindividual comparison . PARTICIPANTS This study included 48 eyes of 24 consecutive patients with age-related cataract . METHODS Each patient had st and ardized small incision cataract surgery with IOL implantation into the capsular bag . Patients were r and omly assigned to receive a blue-light-filtering Hoya AF-1 ( UY ) YA-60BB IOL in one eye and a UV-filtering Hoya AF-1 ( UV ) VA-60BB IOL ( Hoya Medical Europe , Frankfurt/Main , Germany ) in the contralateral eye . Contrast acuity was measured at illumination levels of 500 , 5 , and 0.5 lux and contrast levels of 100 % , 50 % , 25 % , 12.5 % , and 6.25 % . Color vision was assessed using the Lanthony desaturated D-15 test , the Lanthony new color test ( Munsell chroma 2 and 4 ) , and an anomaloscope . Blue/yellow foveal threshold was tested applying short-wave automated perimetry . The subjective visual impression of patients was evaluated using a question naire . MAIN OUTCOME MEASURES Contrast acuity , color vision , and foveal threshold . RESULTS The blue-light-filtering IOLs had worse contrast acuity ( P = 0.0004 ) and foveal threshold ( P = 0.008 ) compared with the UV-filtering IOLs . Color vision tests and high-contrast visual acuity did not show any statistically significant differences between IOLs ( P>0.05 ) . On question ing , 3 of 24 patients noticed a difference between the implanted IOLs concerning visual impression . CONCLUSIONS This study shows that blue-light-filtering IOLs negatively affect contrast acuity and blue/yellow foveal threshold when compared with UV-filtering IOLs . Although the differences were small , the results suggest bilateral implantation of the same IOL type and avoidance of a mixed implantation of a blue-light-filtering IOL in one and a non-blue-light-filtering IOL in the contralateral eye in patients with high dem and s in color vision . FINANCIAL DISCLOSURE(S ) The author(s ) have no proprietary or commercial interest in any material s discussed in this article PURPOSE : To compare best distance visual acuity , color perception , and contrast sensitivity between eyes with an AcrySof Natural intraocular lens ( IOL ) ( Alcon Laboratories Inc. ) and fellow eye with an AcrySof IOL and to compare results in the IOL groups to those in normal , similarly aged patients with clear phakic eyes . SETTING : Sri Sankaradeva Nethralaya , Guwahati , India . METHODS : This prospect i ve r and omized parallel group single‐center patient‐masked examiner‐masked study comprised 26 eyes of 13 healthy patients with bilateral age‐related cataract . All patients had cataract surgery by phacoemulsification in both eyes ; 1 eye received an AcrySof Natural IOL ( SN60AT ) and the fellow eye , an AcrySof ( SA60AT ) IOL . Final postoperative examination was performed at the end of 18 months . In addition to other findings , visual acuity , color perception , and contrast sensitivity were recorded . A group of normal , similarly aged phakic individuals with clear lenses was examined for contrast sensitivity . The records thus obtained were analyzed statistically . RESULTS : The AcrySof and AcrySof Natural IOL groups had a statistically significant improvement in visual acuity and color perception in comparison to preoperative status , and this was maintained until the last postoperative follow‐up at 18 months . There was no statistically significant difference in the findings between the 2 IOL groups . The AcrySof and the AcrySof Natural IOL groups showed significant improvement in contrast sensitivity from the preoperative to the postoperative period ( both P<.001 ) . However , the AcrySof Natural IOL group was better than the AcrySof IOL group when each group was compared separately to similarly aged phakic individuals with clear lenses . CONCLUSIONS : Pseudophakia following AcrySof Natural SN60AT and AcrySof SA60AT IOL implantation led to equivalent visual acuity and color perception . But the contrast sensitivity in the AcrySof Natural group was better and near normal in reference to a healthy , age‐matched control group PURPOSE To study colour vision and retinal nerve fibre layer ( RNFL ) photographs in patients with an Acrysof Natural intraocular lens ( IOL ) .  METHODS We carried out a r and omized double-blind study . An Acrysof Natural IOL ( model SN60AT ) was implanted in 25 eyes of 19 patients and an Acrysof IOL ( model SA60AT ) was implanted in 27 eyes of 18 control patients . The patients returned for colour vision tests and fundus photography 1 - 6 months after the surgery . RESULTS St and ard pseudoisochromatic plates , part 2 , were correctly interpreted and the Farnsworth-Munsell 100-hue test ( FM 100 ) total and individual box scores were normal in all IOL eyes . In the FM 100 hue test there were no significant differences in the results of the total error scores or the error scores of the individual boxes between the eyes with Acrysof Natural and those with Acrysof lenses . The yellow coloration of the Acrysof Natural IOL did not affect the visibility of the RNFL in photographs . CONCLUSIONS The Acrysof Natural IOL did not affect colour vision in the tested patients , even in the blue region of the spectrum , and can be implanted in patients who need to have normal colour vision for the purpose s of their occupation . The Acrysof Natural IOL does not interfere with RNFL photography and can also be used in patients with glaucoma PURPOSE To compare postoperative best distance visual acuity ( VA ) , contrast sensitivity and colour perception with the blue light-filtering AcrySof Natural ( SN60AT ) and AcrySof single-piece ( SA60AT ) intraocular lenses ( IOLs ) . METHODS This was a prospect i ve , r and omized , comparative , interventional study comparing postoperative performance between the SN60 and SA60 IOLs . There were nine patients ( nine eyes ) in the SN60 group and 10 patients ( 10 eyes ) in the SA60 group . All patients were operated using phacoemulsification .  Postoperative VA ( Snellen chart ) , contrast sensitivity ( Pelli-Robson contrast sensitivity chart ) and colour perception ( Farnsworth-Munsell D-15 panel test ) were measured at 1 , 3 and 6 months postoperatively . RESULTS Postoperative best corrected VA after 6 months was 20/20 or better in 89 % of SN60 eyes and 100 % of SA60 eyes . Postoperative contrast sensitivity scores improved significantly in both groups under both photopic and mesopic conditions . There were no statistically significant differences in contrast sensitivity scores between the SN60 and SA60 groups at any of the postoperative evaluation time-points . Postoperative colour perception improved significantly in both the SN60 and SA60 groups , and there were no statistically significant differences in colour perception performance between the two groups . CONCLUSION The blue light-filtering AcrySof Natural ( SN60 ) IOL has postoperative visual performance comparable with that of the AcrySof single-piece ( SA60 ) IOL PURPOSE : To evaluate the effect of blue‐light‐filtering intraocular lenses ( IOLs )  with a yellow chromophore on color contrast sensitivity by intraindividual comparison with an identically design ed IOL without a blue‐light filter . SETTING : Medical University of Vienna , Department of Ophthalmology , Vienna , Austria . METHODS : R and omized implantation of an AF‐1 ( UV ) IOL ( Hoya ) in 1 eye and an AF‐1 ( UY ) IOL ( Hoya ) in the contralateral eye was performed after phacoemulsification and primary posterior curvilinear capsulorhexis . Three months postoperatively , the best distance‐corrected visual acuity was evaluated . Before color contrast sensitivity testing , a heterochromatic flicker test was performed in both eyes to avoid error in brightness matching . Central and peripheral tritan color contrast sensitivities were evaluated using the Moorfields Vision System ( CH Electronics ) . RESULTS : Visual acuity did not differ significantly between the 2 IOL groups ( P>.05 ) . The central color contrast sensitivity threshold also did not differ significantly between eyes with a clear IOL and eyes with a yellow IOL at any tested spatial frequency . The peripheral color contrast sensitivity test showed slightly higher color contrast sensitivity thresholds in eyes with a yellow IOL , although the differences were not statistically significant . Two patients independently reported subjective changes in color perception in the eye with the yellow IOL . CONCLUSION : In this intraindividual comparison , the implantation of a blue‐light‐filtering IOL did not lead to a clinical ly significant change in color contrast sensitivity PURPOSE : To evaluate the results of the first blue light – filtering photochromic intraocular lens ( IOL ) and compare them with those of a regular yellow blue light – filtering IOL and a clear ultraviolet‐filtering IOL in human eyes under various lighting conditions . SETTING : Beijing Tongren Eye Center , Beijing Tongren Hospital , Capital Medical University ; Beijing Ophthalmology & Visual Sciences Key Laboratory , Beijing , China . DESIGN : Prospect i ve comparative clinical study . METHODS : This study evaluated eyes that had implantation of 1 of the following 3 IOLs : photochromic Aurium Matrix acrylic , model 400 ; yellow AF‐1 ( UY ) ; or clear MC611MI . All eyes were followed for 3 months . The uncorrected ( UDVA ) and corrected ( CDVA ) distance visual acuities , contrast vision ( lighting 400 lux , 30 lux , 5 lux ) , contrast sensitivity , color vision ( Farnsworth‐Munsell 100‐hue test under 400 lux , 30 lux ) , and patient question naire responses were evaluated . RESULTS : The  photochromic IOL group comprised 39 eyes ; the yellow IOL group , 41 eyes ; and the clear IOL group , 38 eyes . There were no significant differences between the 3 IOLs in UDVA , CDVA , contrast sensitivity , or question naire responses . The photochromic group had significantly better color vision than the yellow IOL group at 30 lux and better contrast vision at 5 % contrast ( P < .05 ) ; however , there were no significant differences between the photochromic IOL group and the clear IOL group ( P > .05 ) . CONCLUSION : The photochromic blue light – filtering IOL performed as well as the yellow and clear IOLs under photopic conditions . Under mesopic conditions , the yellow IOL gave poor color vision and contrast sensitivity . Financial Disclosure : No author has a financial or proprietary interest in any material or method mentioned PURPOSE : To evaluate contrast sensitivity and glare disability after implantation of an AcrySof IQ Natural SN60WF aspherical intraocular lens ( IOL ) ( Alcon Laboratories ) . SETTING : Iladevi Cataract & IOL Research Centre , Ahmedabad , India . METHODS : One hundred twenty consecutive patients who had phacoemulsification in a prospect i ve triple‐masked trial were r and omized to receive an AcrySof SA60AT IOL ( 40 eyes ) , AcrySof Natural SN60AT IOL ( 40 eyes ) , or AcrySof IQ SN60WF IOL ( 40 eyes ) . At 3 months , contrast sensitivity was measured using the CSV‐1000E contrast sensitivity chart test face ( Vector Vision ) at 3 , 6 , 12 , and 18 cycles per degrees ( cpd ) under photopic conditions ( 85 cd/m2 ) and mesopic conditions ( 2.7 cd/m2 ) with 4.0 mm and 6.0 mm fixed central apertures , with and without glare . The Kruskal‐Wallis test was used and a pair‐wise comparison performed . The main outcome measure was the difference in contrast sensitivity between IOLs at each spatial frequency . RESULTS : The best corrected visual acuity was similar between the 3 IOL groups ( P = .6 ) . The AcrySof IQ group had significantly higher contrast sensitivity at 18 cpd under photopic conditions ( P = .008 ) ; at 3 , 6 , 12 , and 18 cpd during mesopic testing with a 4.0 mm aperture without glare ( P = .018 , P = .011 , P = .007 , and P = .0001 , respectively ) and with glare ( P = .003 , P = .006 , P = .005 , and P = .004 , respectively ) ; and at all spatial frequencies during mesopic testing with a 6.0 mm aperture without glare ( P = .018 , P = .006 , P = .009 , and P = .0001 , respectively ) and with glare ( P = .019 , P = .002 , P = .01 , and P = .017 , respectively ) . CONCLUSION : Eyes with the AcrySof IQ SN60WF IOL had significantly higher contrast sensitivity than eyes with an AcrySof SA60AT or AcrySof Natural SN60AT IOL at all spatial frequencies during mesopic testing ( with and without glare ) with 4.0 and 6.0 mm 
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Conclusion This meta- analysis demonstrates that postoperative visual performance  with blue light-filtering IOLs is approximately equal to that of UV light-filtering IOLs after cataract surgery , but color vision with blue light-filtering IOLs demonstrated some compromise in the blue light spectrum under mesopic light conditions