One should endeavor to keep the two eyes open without winking. One should not open them too wide nor yet close them. The head should be kept steady and the pupils motionless.
If this attempt causes the least wandering of the gaze or the slightest winking of the eyes, it must be begun over again.
It is for this reason that at the start it will be found difficult to keep it up for more than a few seconds.
After resting awhile one should repeat the exercise afresh, until the time comes when one can concentrate one's gaze in this way for at least four or five minutes of perfect fixity.
In order to keep count of the time that is passing, as well as to keep control of one's will-power, it is advisable to count aloud in such a way that approximately one second elapses between the naming of every two numbers.
When once fixity of gaze has been acquired, one can essay various other exercises, such as concentrating the eyes on an object and turning the head slowly to one side and the other without removing one's gaze from this point for a moment.
It is not until one is very certain that the muscles of the eye have been thoroughly trained that one should undertake the mirror test.
To do this, one must take up a position in front of a glass and fix one's gaze upon one's own pupils for a time. Then one must transfer it to the bridge of the nose, between the two eyes, and must strive to keep it there immovably.
At first this exercise will not be found as easy as one might suppose. The magnetic power of the pupils is great and one will experience some slight difficulty in breaking away from it.
For this reason it is a good plan to count out loud slowly up to a predetermined number, at which point the gaze should be at once transferred to the bridge of the nose.