Abraham Lincoln, the 16th President of the United States, was assassinated by John Wilkes Booth on Good Friday, April 14, 1865, while attending the play Our American Cousin at Ford's Theatre in Washington, D.C., as the American Civil War was drawing to a close.
Eye drops have preservatives in them to ensure the sealed product remains sterile until the expiry date. After opening however, the preservative can only ensure the drops are safe for the eye for a period of 28 days. After this, using the drops can cause serious damage to the eye as bacteria may have been introduced. The ingredients themselves will also not be as effective and could be dangerous. Always record the date eye drops are opened and do not use them after 28 days. Some eye drops now have longer expiry dates after opening-always check the packet.
Preservative free single use eye drops have been developed to circumvent this problem, but they come with a hefty price tag. Refrigerators And Eye Drops-Cool Or Not! Most prescription eye drops are OK to use for 30 days after opening if they are kept refrigerated. Most bacteria are inhibited below 40 Â°F and above 140 Â°F. (The listeria bacteria that have been in the Colorado news of late are an exception since they thrive in cooler environments).