Trusted by pharmacists and families in Switzerland for over 35 years, Similasan is a leading Swiss brand of remedies that uses natural active ingredients instead of harsh chemicals to keep families healthy. No harsh vasoconstrictors. Gluten and dairy free. Made with natural active ingredients, not harsh chemicals. Unlike mainstream eye drops, Similasan does not contain benzalkonium chloride preservative. Use Similasan as often as you need. Similasan Style eye Relief drops provide temporary relief from styles (redness, burning, tearing). homeopathic ingredients stimulate your body's natural defenses instead of masking the symptoms.