There are a few kinds of lag. One of them is fps lag, which is completely personal and not determined at all by your connection to the server. Another is block lag, which is caused by a bad connection to the server. I think 'player' lag (that's what I call it) is similar to block lag in that it is caused by a lower connection to the server (but I could be wrong). Also keep in mind that these kinds of lag are not related in any way. You can have block lag without fps lag, and you can have fps lag without block lag. Optifine helps with fps lag, but it does not help with your connection to the server, so you are still equally likely to get block lag and, if I am correct, player lag.