EBAY PAYPAL, PLEASE STOP USING THOSE SECURITY CODES YOU CAN'T READ

Did you ever try to sign into EBAY, PAYPAL or those type of accounts? First you put your user name, then your password and then they offer up some very strange letters or numbers for you to put in. I personally can't read the numbers. I can't figure out whether they are checking your eyes or just messing with you. Once you have put in your user name and password, what is the purpose of putting some letters in you can barely read. What kind of security check is this?
Even if someone had your code, all this would prove is their eyes are better. I hope the sites begin to eliminate these security checks. I am middle aged and my eyes can't read those squirly codes.