It is so bad for eyes to share contact lenses with others. You may have the high possibility to get the eyes infection because of the invisible bacterium. The bacterium in the surface of the contact lenses may let you have eye problems because of the contagious character. You should not do this. It is so dangerous for your health of eyes.
Don't take the risk, and is no point of sharing them for different people have different prescription, unless you are sharing your colored contact lenses. Contact lenses not like glasses, they require hygienic care. Your contact lenses may get abrasions when you share them to others. Abrasion can hurt your eye and get you blurred vision, irritation or redness. Besides this, eye infection is another risk you are taken. People may carry bacteria can contacts lenses can easily transfer the bacteria to your eyes. In a word, eye is the most fragile part of your body, take care of it instead of messing with it.
Increased dangers of eye irritation and infection are caused by sharing contact lenses with others.
First of all, the borrower of contact lenses have increased risk of eye abrasion, because the contact lenses he borrowed from the owner has been fitted well with the owner and won't be fitted well with the borrower.
Secondly, the borrower also has a higher risk of allergies to not only contact lenses, but also the solutions and other related items. After all, one man's meat is another's poison.
Lastly, the bacteria from the origin wearer will possibly be transferred to the second wearer, resulting in eye infection.