Hayashi 2006.

Methods	Study design: RCT Study grouping: parallel group, with bilateral implantation of the same intervention in both eyes, and data averaged between eyes for analyses Exclusions after randomisation: one participant was excluded due to an epi‐retinal membrane (the group assignment was not reported) Losses to follow‐up: of the 80 people enrolled, six were excluded from the analysis; four did not appear for a follow‐up examination because of scheduling conflicts, one refused the examination, and one had a clinically significant epiretinal membrane at the macula. Thus, 74 participants (92.5%) completed the examinations and remained in the analysis. 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): 38 (?) Sex (number of women/number of men): 26/12 Age (mean ± SD): 71.1 ± 6.7 years Non‐blue‐light filtering IOL group Number of participants: number of people (number of eyes): 36 (?) Sex (number of women/number of men): 24/12 Age (mean ± SD): 70.7 ± 6.2 years Inclusion criteria: admission for bilateral cataract surgery Exclusion criteria: pathology of the cornea, retina or optic nerve; a history of ocular surgery or inflammation; a pupillary diameter < 6.0 mm after mydriasis; eyes scheduled for extracapsular cataract extraction; eyes of patients with diabetes; patients who anticipated any difficulty in follow‐up. Comparison of study groups at baseline: "No statistically significant difference was found between the groups (at baseline) regarding age, the ratio of men to women, manifest spherical equivalent, keratometric cylinder or pupillary diameter."
Interventions	Intervention characteristics Blue‐light filtering IOL Type of IOL: YA60BB (Hoya) Non‐blue‐light filtering IOL Type of IOL: VA60BB (Hoya)
Outcomes	Visual acuity, contrast visual acuity with and without a glare source under photopic (100 cd/m2) and mesopic (slightly higher luminance than typically used ‐ 5 cd/m2) conditions at two weeks and three months after surgery using the contrast sensitivity accurate tester The incidence of participants who noted cyanopsia at three months after surgery
Identification	Sponsorship source: Funding sources: not reported Declaration of interest: "The authors have no proprietary interest in any of the materials described in this article" Country: Japan Setting: Hayashi Eye Hospital, 4‐7‐13 Hakataekimae, Hakata‐ Ku, Fukuoka 812, Japan Comments: Date study conducted: 3 November 2004‐20 April 2005 Trial registration number: not reported Contacting study investigators: study authors not contacted; no additional information used for the review Corresponding author's name: Ken Hayashi Institution: Hayashi Eye Hospital Email: hayaski‐ken@hayashi.or.jp Address: Hayashi Eye Hospital, 4‐7‐13 Hakataekimae, Hakata‐ Ku, Fukuoka 812, Japan
Notes	None
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "The clinical research coordinator generated a code using a random number table." Judgement comment: the randomisation sequence was generated using a random number table by the research co‐ordinator.
Allocation concealment (selection bias)	Unclear risk	Judgement comment: method of allocation concealment not specified
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "Patients and examiners were masked to the randomisation." Judgement comment: clearly stated that participants and personnel not aware of which treatment received
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "Patients and examiners were masked to the randomisation. The surgeon, who was also the data analyst, did not participate in any of the examinations or in the data collection." Judgement comment: clearly stated that outcome assessors were masked
Incomplete outcome data (attrition bias) All outcomes	Low risk	Quote: "Of the 80 patients enrolled, six were excluded from the analysis; four did not appear for a follow up examination because of scheduling conflicts, one refused the examination, and one had a clinically significant epiretinal membrane in the macula. Thus, 74 patients (92.5%) completed the examinations and remained in the analysis." Judgement comment: missing data less than 20% (i.e., more than 80% follow‐up) and relatively equal follow‐up in both groups 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 source of bias