Yes, it's a sign of eye irritation. When you're inserting or taking off the contact lenses, foreign materials would irritate your eyes through unclear hands. In general, foreign materials that include bacteria, viruses and allergens can lead to eye irritation. There are some symbols can help you to identify whether you get eye irritation. As you said, the redness of eyes lead to eye irritation, especially the eyelid becomes red and swollen. And exposure to water, soap around the eye would be painful thus one cause of eye irritation. And the irritated eyes produce more tears than normal, which would cause by dry eyes. Additionally, your eyelashes would be crusted when you're waking up in the morning because there is more mucus produced at night. And it's not easy to remove the mucus, you need to pay attention to it, it's a sign of eye irritation.
The symptoms of irritated eyes may conclude: the eye is getting dry and itching. Sometimes they are bloodshot. If your eyes get red after wearing the contact lenses, you should pay attention to the following two conditions.
First, it is possibly for you to catch the acute hyperemia of eye. For example, you have been wearing glasses too tight for a long time. You have the habit of wearing your glasses to sleep. You even often wear with the polluted lenses of contacts, etc. All these may cause the bacterial infection on your eye. At this moment, you single eye may be affected usually. If it is more serious like painful, tearful, irritated and even vague, we say you may be infected the keratitis.
Second, you may get the chronic hyperaemia, which mainly happen light hyperaemia of the conjunctiva between the corneal limbal parts and the inner/outer corner of eye. The reason may be unclean wash of the antiseptic liquid medicines with irritated and allergic smells.
Besides, the lens of contact lenses become old and degenerated, whose sediments piled together and led to the congestion. The congestion or hyperaemia above I mentioned was the symptoms of eye getting red. As long as you discover these symptoms, you'd better go to hospital for a detailed check and get a completed heal for your case.