Vuori 2006.

Methods	Study design: RCT Study grouping: parallel group, involving 37 people (52 eyes) Exclusions after randomisation: not reported Losses to follow‐up: not reported How missing data were handled: in the photographic analysis, two eyes of one participant in the Acrysof Natural IOL group were excluded because of a very lightly pigmented fundus Reported power size calculation? no
Participants	Baseline characteristics Blue‐light filtering IOL group Number of participants (number of eyes): 19 (25) Sex (number of women/number of men): not reported Age (mean ± SD): 72 ± 8 years Non‐blue‐light filtering IOL group Number of participants (number of eyes): 18 (27) Sex (number of women/number of men): not reported Age (mean ± SD): 73 ± 7 years Inclusion criteria: white patients scheduled for phacoemulsification and IOL implantation Exclusion criteria: hereditary colour vision defects; medications that might affect colour vision, such as ethambutol; any medication for epilepsy; amiodarone; digitalis; anti‐inflammatory drugs; diabetes; any other ocular pathology except cataract Comparison of study groups at baseline: no apparent group differences, although this was not explicitly stated and sex of participants was not given
Interventions	Intervention characteristics Blue‐light filtering IOL Type of IOL: Acrysof Natural ‐ model SN60AT (Alcon) Non‐blue‐light filtering IOL Type of IOL: Acrysof ‐ model SA60AT (Alcon)
Outcomes	Colour vision (measured using Standard pseudoisochromatic plates, part 2, (SPP2) (Ichikawa et al. 1983) and the FarnsworthMunsell 100‐hue test (FM 100) (Farnsworth 1957)) and visibility of the retinal nerve fibre layer, from retinal fundus photography at one to six months postoperatively
Identification	Sponsorship source: Funding sources: not reported Declaration of interest: not reported Country: Finland Setting: Department of Ophthalmology, Turku University Hopsital, Turku, Finland 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: Marja‐Liisa Vuori, MD Institution: Department of Ophthalmology Turku University Hospital, Kiinamyllynkatu 4–8, 20520 Turku, Finland Email: marja‐liisa.vuori@tyks.fi Corresponding author's address: Marja‐Liisa Vuori Department of Ophthalmology Turku University Hospital Kiinamyllynkatu 4–820520 Turku, Finland
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)	Low risk	Quote: "Sealed envelopes containing the code for the planned IOL type were used for randomization.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Judgement comment: described as “double blind” with no information on who was masked
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Judgement comment: described as “double blind” with no information on who was masked
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Judgement comment: results suggest no participants were lost to follow‐up; although this is not explicitly stated
Selective reporting (reporting bias)	Unclear risk	Judgement comment: no access to protocol or trials registry entry
Other bias	Unclear risk	Judgement comment: sex distribution between study groups at baseline is not reported; the significance of this baseline imbalance is not clear