how can i find out when the eye drops are working how do i find the difference between eye drops how many times a day should an eye drop be evaluated? longitudinal paired analysis definition how do you find time difference between two eyes how to determine difference between eyes after eye drops how to calculate a time difference between the eyes how to measure the effect of a new eye drop what should you calculate for each eye drop how to calculate difference between eyes when combining eye drops longitudinally how to calculate difference between eyes what is meant by paired measure in longitudinal analysis which model is used to test for ocular drops longitudinal paired analysis how do you get the difference between the eyes how to measure long term difference when is a measure of treatment based on a paired analysis how long does it take for a measure of change in eye drops how to determine how many times the eye drops work how longitudinal paired analysis work