REFRESH OPTIVE ® contains not just one, but two active ingredients that help relieve dry, burning, irritated eyes due to Dry Eye. This specially designed, preservative-free formula provides long-lasting moisture that hydrates and protects the cells of the eye that can become damaged due to Dry Eye. And, since REFRESH OPTIVE ® is preservative-free, it is gentle enough for sensitive eyes. It is also recommended for post-LASIK dryness. If you have recently had LASIK surgery, please follow your eye doctor’s instructions regarding the use of REFRESH OPTIVE ® Preservative-Free. REFRESH OPTIVE ® Preservative-Free Lubricant Eye Drops come in sterile, single-use vials you can take with you anywhere. They are safe to use as often as needed.
The increasing demand for ready-to-eat fresh food products has led to challenges for food distributors regarding the safety and quality of their foods. Artificial preservatives meet some of these challenges by preserving freshness for longer periods of time, but these preservatives can cause negative side-effects as well. Sodium nitrite is a preservative used in lunch meats, hams , sausages , hot dogs , and bacon to prevent botulism . It serves the important function of controlling the bacteria that cause botulism , but sodium nitrite can react with proteins , or during cooking at high heats, to form carcinogenic N-nitrosamines .  [ unreliable medical source? ] It has also been linked to cancer in lab animals.  The commonly used sodium benzoate has been found to extend the shelf life of bottled tomato paste to 40 weeks without loss of quality.  However, it can form the carcinogen benzene when combined with vitamin C . [ citation needed ] Many food manufacturers have reformed their products to eliminate this combination, but a risk still exists.  Consumption of sodium benzoate may also cause hyperactivity . For over 30 years, there has been a debate about whether or not preservatives and other food additives can cause hyperactivity . Studies have found that there may be increases in hyperactivity amongst children who consume artificial colorings and benzoate preservatives and who are already genetically predisposed to hyperactivity, but these studies were not entirely conclusive. Hyperactivity only increased moderately, and it was not determined if the preservatives, colorings, or a combination of the two were responsible for the increase.