Why do some drops have a red cap?

Red caps indicate pupil-dilating mydriatics and cycloplegics. They can cause light sensitivity and near blur and should not be used as redness relievers or lubricants.

Why is my prostaglandin cap sometimes clear instead of teal?

Teal is the usual prostaglandin color, but generics or unit-dose packaging may be clear or white. If the cap looks different, confirm the drug name and strength on the label.

What is the difference between tan and pink caps?

Tan usually indicates antibiotics, while pink indicates steroids. Confusing them can worsen infectious keratitis, so the difference should be emphasized in counseling.

Eye Drop Cap Color Codes

Recommended color coding by drug class

Color Codes for Ophthalmic Medications

AAO cap color coding and why it matters

The American Academy of Ophthalmology (AAO) promotes a voluntary cap color-coding system for topical ocular medications to reduce dispensing errors and simplify complex regimens. When patients are using multiple drops, for example glaucoma therapy plus dry eye and allergy management, consistent cap colors provide an extra safety cue when labels are hard to read or vision is reduced. The table on this page summarizes common color associations by drug class.

Clinical safety and high-risk mix-ups

Cap color is a helpful cue, but it is not a substitute for verifying the label. Safety-critical distinctions such as tan caps (anti-infectives) versus pink caps (steroids) should be reinforced in counseling to reduce the risk of using a steroid on infectious keratitis. Red caps identify mydriatics and cycloplegics, and patients should be told these drops will dilate the pupil, blur near vision, and increase light sensitivity.

Generics, packaging differences, and refill checks

Generic manufacturers and compounding pharmacies can deviate from standard AAO colors because of packaging or supply constraints. For example, some prostaglandin products may appear with clear or white caps rather than teal. If a refill looks different, instruct patients to confirm the drug name and strength on the label before use. In the clinic, confirm class and indication when switching between branded and generic versions to keep education and workflows consistent.

Cap Color Chart by Medication Class

Class	Color
Adrenergic agonist combinations	Light Green
Adrenergic agonists	Purple
Anti-infectives	Tan
Anti-inflammatory, non-steroidal	Gray
Anti-inflammatory, steroids	Pink
Anti-inflammatory, immunomodulators	Olive Green
Beta-blocker combinations	Dark Blue
Beta-blockers	Yellow
Carbonic anhydrase inhibitors	Orange
Cytotoxic	Black
Miotics	Dark Green
Mydriatics and cycloplegics	Red
Prostaglandin analogues	Turquoise

Cap Color FAQs

Why do some drops have a red cap?: A red cap indicates a mydriatic or cycloplegic agent such as atropine or cyclopentolate. These drops dilate the pupil and reduce accommodation. Counsel patients that red-cap drops can cause light sensitivity and near blur and should not be used as redness relievers or lubricants.
Why is my prostaglandin cap sometimes clear instead of teal?: Teal is the standard color for prostaglandin analogs such as latanoprost, but some generic products or preservative-free unit-dose packaging may use clear or white caps and containers. If the cap color changes between refills, instruct patients to confirm the drug name and strength on the label before use.
What is the difference between tan and pink caps?: Tan caps typically identify anti-infective agents such as antibiotics, while pink caps identify topical corticosteroids. This distinction is safety-critical because using a steroid instead of an antibiotic on infectious keratitis can worsen the condition. Reinforce this difference whenever both classes are prescribed or when a patient is unsure which bottle is which.