einstein (São Paulo). 11/Dec/2018;17(1):eAO4410.

When color helps

Ana Luiza Fontes de Azevedo Costa ORCID logo , Thiago Gonçalves dos Santos Martins ORCID logo , Ricardo Vieira Martins ORCID logo , Paulo Schor ORCID logo

DOI: 10.31744/einstein_journal/2019AO4410



To reduce the inappropriate identification of eye drops, through the use of different colors.


A group of 34 healthy volunteers was presented to two groups of four eye drops each. All eye drops were placed in identical, unlabelled vials. In one group, all four eye drops were transparent. In the other group, each had a different color. A number was assigned to each eye drop, and the volunteer was asked to identify it by color. We measured the correct index in the identification of the eye drops of the two groups.


The volunteers had a level of education from incomplete junior school to complete graduate course, with 16 males (48%) and 18 females (52%), age range of 21 to 87 years. The success rate in the group of colored eye drops was 88% and, in the group of transparent, 24%.


The use of colorings in eye drops can help distinguishing the vials and preventing misidentification.

When color helps