science

Visine

Visine is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Visine rather than just read about it. In short: Visine (), also known as Vispring, is a brand of eye drops produced by Kenvue. Visine was first introduced in 1958 and was acquired by Pfizer in 1999.

Key takeaways

Visine belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Visine to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Visine from memory before moving on to harder problems.

Reference excerpt

Visine (), also known as Vispring, is a brand of eye drops produced by Kenvue. Visine was first introduced in 1958 and was acquired by Pfizer in 1999. In 2006, Johnson & Johnson acquired Visine, along with Pfizer's entire consumer healthcare portfolio. The original formulation of Visine includes the active ingredient tetrahydrozoline hydrochloride, which is a vasoconstrictor that constricts the eye's superficial blood vessels to temporarily reduce eye redness.

Products In addition to its original formulation, Visine is available in several varieties of eye drops for different types of eye irritation. These include formulas with antihistamines for allergy-induced irritation, to moisturizing formulations for eye dryness. These formulations use active ingredients ranging from oxymetazoline to naphazoline. Some Visine products cater specifically to contact lens wearers or to those who require artificial tears.

Side effects

Adverse effects Visine has been observed to cause stinging and burning upon application, and has a rebound effect that may cause eye redness to worsen. Prolonged use has been observed to cause blood vessels to be dilated for an extended period of time. Because of this risk, Visine usage has been recommended to be limited, unless specified by a doctor. Some formulations of Visine are not advised for contact lens wearers as the decreased blood flow to counter eye redness could further lower oxygen levels to the eye. Some Visine products are not recommended to be used by patients with glaucoma, since stimulation from lubrication can contribute to high pressure within the eye. Certain underlying health conditions that cause eye irritation are not able to be relieved by Visine and require prescription-grade eye drops.

Ingestion A debunked urban legend claims that a few drops of Visine will cause harmless but debilitating bouts of explosive diarrhea, similar to a laxative. However, symptoms of Visine's active ingredient tetrahydrozoline hydrochloride can be severe, and can include:

Dangerously low body temperature (hypothermia) Blurred vision Nausea and vomiting Difficulty breathing or cessation of breathing Elevated blood pressure (hypertension) followed by sudden low blood pressure (hypotension) Coma Seizures and tremors Death Oral ingestion of Visine warrants immediate medical attention or a call to a poison control center. The film Wedding Crashers misrepresents the effects of Visine consumption which can be lethal.

Criminal use There have been multiple high-profile murder cases that have been alleged to utilize Visine's active ingredient tetrahydrozoline hydrochloride as a poison. In 2018, a South Carolina nurse was accused of killing her husband by adding Visine to his drinks over a period of three days. In 2019, a North Carolina paramedic was similarly accused of murdering his wife, with Visine misuse asserted as the probable cause.

References

External links Visine webpage Snopes reference

Illustrations

Worked examples

Example 1 — a first encounter with Visine

Start with the simplest possible case. Write down what Visine claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Visine before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Visine ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Visine

In research: Visine appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Visine in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Visine is common in secondary-school and first-year university syllabi. It links to neighbouring topics Drugs developed by Johnson & Johnson, Ophthalmology drugs, so understanding it makes those chapters shorter.
In everyday life: Look for Visine outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Visine in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Visine means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Visine out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Visine in simple terms?

Visine (), also known as Vispring, is a brand of eye drops produced by Kenvue. Visine was first introduced in 1958 and was acquired by Pfizer in 1999.

Why does Visine matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Visine?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Visine.