[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Ophthalmology](https://durgical.com/en/ophthalmology/) › [The eye exam](https://durgical.com/en/ophthalmology/areas/exam/) › Fluorescein staining and the Seidel test # Fluorescein staining and the Seidel test - Examination Fluorescein glows green under blue light where the corneal surface is broken. The pattern names the cause; a stream of diluted dye means an open wound. Updated Nov 5, 2026 **See it in 3D:** [Cornea](https://durgical.com/en/anatomy/cornea/) ## Key points - Dendrite = herpes simplex: no steroids. - Vertical scratches = evert the upper lid. - Positive Seidel = full-thickness wound. - Remove soft contact lenses before fluorescein. ## What it is Fluorescein is an orange dye that pools where the corneal or conjunctival epithelium is missing and glows bright green under cobalt blue light. It shows abrasions, ulcers, dendrites, dry-eye spots and foreign-body tracks. It also measures how fast the tear film breaks up. In the Seidel test, concentrated dye painted over a wound turns into a green stream if aqueous humour leaks out, proving a full-thickness wound. ## Normal values and scales - Geographic stain after injury: abrasion. - Branching line with terminal bulbs: herpes simplex dendritic ulcer. - Fine dots over the lower cornea: dry eye, exposure or drug toxicity; diffuse dots in both eyes after welding or sun: ultraviolet keratitis. - Vertical linear scratches: a foreign body under the upper lid. - Tear break-up time under about 10 seconds suggests an unstable tear film. ## How it is done - Ask the patient to remove soft contact lenses, which absorb the dye. - Moisten a fluorescein strip with saline and touch it to the lower conjunctiva, or instil a drop of dye with anaesthetic. - Ask the patient to blink, then examine with cobalt blue light (slit lamp, ophthalmoscope filter or blue penlight). - Describe the shape, size and position of any staining area, and look under the upper lid. - Seidel test: apply concentrated dye directly over a suspected wound without pressing and watch for a dark stream through the green dye. - Tear break-up time: count the seconds from a blink to the first dry spot. ## How to interpret it - A positive Seidel test means a full-thickness corneal or scleral wound: stop and treat as an open globe. - A dendrite contraindicates topical steroids. - A white infiltrate under a staining defect means infection (ulcer), not just an abrasion. ## Next step / Initial management - Simple abrasion: topical antibiotic, analgesia and review if not healed in 24 to 48 hours. - Dendritic ulcer, infiltrate or staining in a contact lens wearer: same-day ophthalmology. - Positive Seidel test: shield, nothing by mouth and emergency referral. - Punctate staining with dry-eye symptoms: lubricants and treatment of lid disease. ## Test yourself Think of the answer, then tap the question to see it. ## What does a branching fluorescein-staining lesion with terminal bulbs indicate? A herpes simplex dendritic ulcer; topical steroids must be avoided. ## What is a positive Seidel test? Concentrated fluorescein over a wound is diluted by leaking aqueous into a visible stream, proving a full-thickness wound. ## Why are soft contact lenses removed before fluorescein? Because they absorb and are stained by the dye. [Add to my cards (3)](https://durgical.app/estudiar/?add=/en/ophthalmology/fluorescein-staining-and-the-seidel-test/) ## Connections ## See it in 3D 1 The structures of Durgical's 3D anatomy where it is found. - [Cornea](https://durgical.com/en/anatomy/cornea/) ## Related 5 - [The slit lamp: what each light shows](https://durgical.com/en/ophthalmology/the-slit-lamp-what-each-light-shows/) - [Corneal and subtarsal foreign bodies](https://durgical.com/en/ophthalmology/corneal-and-subtarsal-foreign-bodies/) - [Red eye: what is serious and what is not](https://durgical.com/en/ophthalmology/red-eye-what-is-serious-and-what-is-not/) - [Suspected open globe: the first steps](https://durgical.com/en/ophthalmology/suspected-open-globe-the-first-steps/) - [The tear film and ocular surface](https://durgical.com/en/ophthalmology/the-tear-film-and-ocular-surface/) ## Related conditions 5 - [Corneal abrasion and ocular foreign body](https://durgical.com/en/conditions/corneal-abrasion-and-ocular-foreign-body/) - [Keratitis and corneal ulcer](https://durgical.com/en/conditions/keratitis-and-corneal-ulcer/) - [Dry eye disease](https://durgical.com/en/conditions/dry-eye-disease/) - [Genital herpes (herpes simplex infection)](https://durgical.com/en/conditions/genital-herpes/) - [Ocular trauma: hyphema and open globe injury](https://durgical.com/en/conditions/ocular-trauma-hyphema-and-open-globe-injury/) ## In Pharmacology 2 - [Fluorescein](https://durgical.com/en/pharmacology/fluorescein/) - [Tetracaine](https://durgical.com/en/pharmacology/tetracaine/) [← All of ophthalmology](https://durgical.com/en/ophthalmology/) Educational content; not a clinical guideline and no substitute for assessment by a health professional. For sudden visual loss, severe eye pain, a chemical burn or an eye injury, go to an emergency department at once. Sources: [Fluorescein](https://www.ncbi.nlm.nih.gov/books/NBK555957/) (StatPearls Publishing (NCBI Bookshelf), 2026); [Seidel Test](https://www.ncbi.nlm.nih.gov/books/NBK541019/) (StatPearls Publishing (NCBI Bookshelf), 2022); [Corneal Abrasion](https://www.ncbi.nlm.nih.gov/books/NBK532960/) (StatPearls Publishing (NCBI Bookshelf), 2024). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/ophthalmology/fluorescein-staining-and-the-seidel-test/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/ophthalmology/fluorescein-staining-and-the-seidel-test/