What does Blink BID (twice a day) OU (oculus uterque, both eyes) mean?

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Medical Abbreviation: "Blink BID OU"

"Blink BID OU" is a prescription instruction meaning to instill artificial tears (typically referring to a brand name lubricant eye drop) twice daily (BID = bis in die) in both eyes (OU = oculus uterque).

Abbreviation Breakdown

  • Blink = Brand name for an over-the-counter artificial tear product 1
  • BID = Latin abbreviation "bis in die" meaning twice daily, approximately 12 hours apart 2
  • OU = Latin abbreviation "oculus uterque" meaning both eyes 3

Clinical Context and Usage

This prescription format is commonly used for managing dry eye disease, where artificial tears serve as first-line therapy 3, 4:

  • Dosing schedule: Instill one drop in each eye twice daily, typically spaced approximately 12 hours apart 2
  • Application technique: Patients should be instructed to avoid touching the vial tip to the eye or any surface to prevent contamination and potential eye injury 2

Important Clinical Considerations

Timing with Other Eye Medications

  • If using multiple topical eye medications, allow a 15-minute interval between different products to prevent dilution and washout 2
  • This spacing applies to both prescription medications and other lubricant drops 2

Contact Lens Wear

  • Artificial tears should not be administered while wearing contact lenses 2
  • Patients with decreased tear production typically should not wear contact lenses 2
  • If contact lenses must be worn, remove them prior to instillation and wait 15 minutes before reinserting 2

Frequency Considerations

  • While BID dosing is prescribed, patients with dry eye disease often require more frequent application based on symptom severity 3
  • However, frequent use of preserved eye drops (>4 drops daily) can cause corneal epithelial breakdown 5, 4
  • For patients requiring more than 4 applications daily, preservative-free formulations should be recommended 5, 4

Common Pitfalls to Avoid

  • Contamination risk: Emphasize not touching the dropper tip to any surface, as this is a frequent source of ocular infection 2
  • Medication washout: Failure to space multiple eye medications by 15 minutes reduces efficacy of all products 2
  • Preservative toxicity: Overuse of preserved artificial tears (>4 times daily) paradoxically worsens dry eye through epithelial damage 5, 4

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Guideline

Dry Eye Disease Causes and Risk Factors

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

Guideline

Nocturnal Dry Eye Causes and Mechanisms

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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