The mind can easily be fooled by the illusion created by familiarity, expectancy, similarity, and experience; this phenomenon is known as confirmation bias or inattentional blindness.16 In other words, the brain sees what it wants to see because of four factors: conspicuity, mental workload, expectation, and capacity.16 It's the failure to see something because attention isn't focused on it or the brain inadvertently filters out important information.16 Essentially, this is a kind of optical illusion that occurs when the brain “auto-corrects” for what the nurse expects to see. Examples of confirmation bias that contribute to medication errors include look-alike and sound-alike drugs, decimal point placement, units of measurement, size and type of font, incorrect drug calculations, frequency of administration, similar packaging, and the use of unapproved abbreviations. The nurse may see the drug name on the label, drug, or dose but interpret it incorrectly.