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.
1 This medicine may cause your vision to blur temporarily after you have applied it into your eye. Do not drive or operate machinery until this has worn off.  Liquifilm tears eye drops should be discarded four weeks after the first opening. You may find it helpful to write the date of opening on the pack.