Schmidinger 2008.

Methods	Study design: RCT Study grouping: parallel group, with paired‐eye comparison (i.e., one eye received a blue‐light filtering IOL and the fellow eye received a non‐blue‐light filtering IOL) Exclusions after randomisation: of the 31 participants (enrolled), one was excluded because of subjectively disturbing vitreous floaters and two because of previously undetected macular drusen Losses to follow‐up: not reported How missing data were handled: not reported Reported power size calculation? no
Participants	Baseline characteristics Blue‐light filtering IOL group Number of participants: number of people (number of eyes): 31 (31) Sex (number of women/number of men): not reported Age (mean ± SD): 73.4 ± 7.64 years Non‐blue‐light filtering IOL group Number of participants: number of people (number of eyes): 31 (31) Sex (number of women/number of men): not reported Age (mean ± SD): 73.4 ± 7.64 years Inclusion criteria: people with no history of corneal disorders, no abnormal pupil reaction, no sign of inflammation, no opacification of optic media apart from cataract, and no retinal disorders. Exclusion criteria: people with systemic disease or those having treatment known to affect colour perception. Based on specular microscopy, patients with evident signs of macular alteration or other ocular disease after surgery. Comparison of study groups at baseline: all participants had a similar cataract grade in both eyes. Baseline age was reported for 28 of the 31 participants. It should be noted that "patients with evident signs of macular alteration or other ocular disease after surgery were not included in the study", however "no intraoperative or postoperative complications or adverse events occurred."
Interventions	Intervention characteristics Blue‐light filtering IOL Type of IOL: AF‐1 (UY) (Hoya) Non‐blue‐light filtering IOL Type of IOL: AF‐1 (UV) (Hoya)
Outcomes	Distance BCVA, colour contrast sensitivity (measured using heterochromic flicker), central and peripheral tritan colour contrast sensitivities (measured using the Moorfields Vision System, CH Electronics) at three months postoperatively. The primary outcome measure was colour contrast sensitivity for short wavelengths of visible light at three months postoperatively.
Identification	Sponsorship source: Funding sources: not reported Declaration of interest: no author had a financial or proprietary interest in any material or method mentioned Country: Austria Setting: Medical University of Vienna, Department of Ophthalmology, Vienna, Austria Comments: Date study conducted: not reported Trial registration number: not reported Contacting study investigators: study authors not contacted; no additional information used for review First author's name: Gerald Schmidinger, MD Institution: Department of Ophthalmology, Medical University of Vienna Email: gerald.schmidinger@meduniwien.ac.at Corresponding author's address: Gerald Schmidinger Department of Ophthalmology, Medical University of Vienna Waehringer Guertel 18‐20, A‐1090 Vienna, Austria
Notes	None
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Judgement comment: not reported how list was generated. Study is described as “randomised” but with no further details
Allocation concealment (selection bias)	Unclear risk	Judgement comment: not reported how allocation administered. Study is described as “randomised” but with no further details
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Quote: "double‐blind study" Judgement comment: study is described as "double‐blind" without specific information on how participants and personnel were masked
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "The investigator performing the test was blind to the type of IOL implanted." Judgement comment: clearly stated that outcome assessors were masked
Incomplete outcome data (attrition bias) All outcomes	Low risk	Judgement comment: missing data less than 20% (i.e., more than 80% follow‐up) and no obvious reason why loss to follow‐up should be related to outcome
Selective reporting (reporting bias)	Unclear risk	Judgement comment: no access to protocol or trials registry entry
Other bias	Low risk	Judgement comment: no other apparent sources of bias