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General product information only, not medical advice. Whether a plug is suitable for any person is a decision for their eye-care clinician.
Short answer
A collagen punctal plug is a temporary tear-duct occlusion device made of animal collagen that dissolves on its own, usually within days to a couple of weeks depending on the source and product. Longer-lasting types include silicone, which EyeWiki describes as the usual material for canalicular plugs. Collagen plugs are also known as dissolvable or temporary plugs, and FDA lists “plug, punctum” under the product code LZU as Unclassified (pre-amendment).
What is a punctal plug?
The American Academy of Ophthalmology’s EyeWiki describes punctal plugs as “a type of occlusion device inserted into the tear duct of an eye to prevent drainage of tears” (checked 2026-10-30). A 2016 review of the literature on existing punctal plugs adds that lacrimal occlusive devices block tear drainage to conserve natural tears, and distinguishes punctal plugs, which sit at the punctal opening, from canalicular plugs, which sit inside the canaliculus (PMC4800096, checked 2026-10-30).
This page covers product characteristics only. It does not describe how a clinician places or removes a plug, and it gives no guidance on whether anyone should have one.
Types of punctal plugs: collagen, polydioxanone, silicone and others
The two sources agree on the broad grouping: plugs are classed by how long they last, and the material largely determines that. The table lists only what each source states.
| Material or group | Duration as stated by the source | Source |
|---|---|---|
| Collagen (temporary, short duration) | Dissolves about 1 to 2 weeks after insertion | EyeWiki, Punctal Plugs |
| Collagen (temporary, short duration; usually animal collagen) | Lasts about 4 to 14 days | PMC4800096 |
| Polydioxanone (temporary, extended) | Dissolves about 3 to 6 months | EyeWiki, Punctal Plugs |
| Silicone | Canalicular plugs are most commonly made of silicone; longer lasting | EyeWiki, Punctal Plugs |
| Thermosensitive acrylic (for example SmartPlug) | Longer lasting; changes shape at body temperature | EyeWiki, Punctal Plugs |
Collagen punctal plugs
The review describes short-duration temporary plugs as usually made of animal collagen, and notes the collagen is usually bovine. EyeWiki names Soft Plug collagen and UltraPlug as examples.
Silicone punctal plugs
EyeWiki says canalicular plugs are most commonly made of silicone, and names the opaque silicone Herrick plug as one example, whose widened posterior segment is designed to limit migration.
Other materials
EyeWiki lists a thermosensitive acrylic plug (SmartPlug, supplied at 6 mm by 0.4 mm and shortening to about 1.5 mm by 1 mm once warmed inside the canaliculus) and a hydrogel plug (Form Fit). It also mentions punctal cauterization as an alternative to plugs, which is a different intervention and not a plug.
Punctal plug sizes
EyeWiki states that the diameter of the punctum or canaliculus is measured with a punctal gauge to determine the appropriate plug size. Published size ranges in the review give a sense of scale: collagen plugs listed in 3 sizes of 0.2 to 0.4 mm, and the EaglePlug in 5 sizes of 0.4 to 0.8 mm. The review adds that for canalicular plugs the diameter matters more than the length. Some products are sold as single-size designs; EyeWiki lists the Painless Punctal Plug as “one-size-fits all”. The typical plug shape in the review is an umbrella form with a head, neck and cone base.
Regulatory classification: what FDA says about punctal plugs
FDA’s product classification database lists the device name “plug, punctum” under product code LZU, in the Ophthalmic panel, with device class “Unclassified” and the reason “Pre-Amendment” (checked 2026-10-30). No regulation number is listed for that code. Pre-amendment devices are those marketed before the Medical Device Amendments took effect; see Medical Device Amendments of 1976 for background and FDA De Novo classification for a different route to a classification.
Checklist for comparing punctal plug products
Drawn only from the facts above, these are the attributes a product record should state clearly so that two plugs can be compared like for like:
- Material (collagen, polydioxanone, silicone, acrylic or hydrogel), because the sources tie duration to material.
- Labelled duration in the manufacturer’s instructions for use. Sources quote different ranges (4 to 14 days, 1 to 2 weeks), so the label governs, not a general figure.
- Punctal or canalicular design, since the two sit in different places.
- Listed size or size range, and whether the product is single-size.
- FDA product code and classification status as recorded in FDA’s database.
Common misunderstandings
- Collagen means permanent. No. Collagen plugs are the temporary, dissolving group; the sources give days to a couple of weeks.
- All plugs are silicone. Silicone is the most common material for canalicular plugs, but collagen, polydioxanone, acrylic and hydrogel plugs are also described.
- A punctal plug is the same as a scleral plug. No. Under 21 CFR 886.4155 a scleral plug is a prescription device that temporarily closes a scleral incision during eye surgery, and it is Class II. Punctal plugs are a separate product code (LZU).
- Plugs carry no risks. EyeWiki lists complications including plug loss, foreign body sensation, epiphora, extrusion, migration, pyogenic granuloma, canaliculitis, dacryocystitis and corneal injury.
FAQ
What is a punctal plug?
It is an occlusion device placed in the tear duct to reduce tear drainage, as defined by EyeWiki (checked 2026-10-30).
How long do collagen punctal plugs last?
Sources differ: about 4 to 14 days in the 2016 review and about 1 to 2 weeks in EyeWiki. The product’s own instructions for use give the labelled duration.
What types of punctal plugs are there?
By duration: temporary short (collagen), temporary extended (polydioxanone) and longer-lasting or permanent types such as silicone, acrylic and hydrogel. By position: punctal or canalicular.
What are silicone punctal plugs?
EyeWiki says canalicular plugs are most commonly made of silicone, which is not a dissolving material.
What sizes do punctal plugs come in?
Published ranges include collagen plugs in 3 sizes of 0.2 to 0.4 mm and one product in 5 sizes of 0.4 to 0.8 mm; some are single-size.
Sources
- American Academy of Ophthalmology, EyeWiki, “Punctal Plugs”, https://eyewiki.aao.org/Punctal_Plugs, checked 2026-10-30.
- “Comprehensive Review of the Literature on Existing Punctal Plugs for the Management of Dry Eye Disease”, PMC4800096, https://pmc.ncbi.nlm.nih.gov/articles/PMC4800096/, checked 2026-10-30.
- FDA Product Classification database, product code LZU, https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpcd/classification.cfm?ID=LZU, checked 2026-10-30.
- 21 CFR 886.4155 (scleral plug), https://www.ecfr.gov/current/title-21/section-886.4155, checked 2026-10-30.
Related reading: what an ophthalmoscope is, ophthalmology research areas, the FDA.
