According to the Hatha Yoga Pradipika, Candle Gazing "cures diseases of the eyes and removes tiredness." 

It also focuses the mind, improves concentration, and is very calming. As such, it is a very good preparation for meditation. If possible, practice in a darkened room.

Light a candle or an oil lamp and place it on a low table, so that it will be exactly level with the eyes. 

Sit on the floor using a comfortable meditation posture, so there is a distance of about 1.25 yards (1 meter) between the face and the flame. 

Keep the back straight and the shoulders relaxed.

1- Decide in advance how long you would like to gaze at the flame.

In the beginning, thirty, forty-five or sixty seconds is realistic. 

Although you can't look at a clock, do your best to stick to yourself. 

Then this exercise will develop your equanimity and internal resilience. While initially it will be difficult to gaze at the flame without blinking for more than a few moments, this will become noticeably easier with practice. Over weeks of practice, gradually increase the gazing time from one to three minutes.

2 - Gaze at the flame steadily without blinking or moving the eyes. Keep your attention totally focused on the flame. Your eyes may begin to water or you may experience some distortions of your vision. This is normal. Keep a steady

mind and resist the urge to blink. When your set time is up, close the eyes gently.

3 - With eyes closed, an after-image of the flame may appear. Observe it in your mind's eye, like a focal point for your meditative mindset. When it disappears, begin your next round of gazing.

4- At the end of the third round, rub your hands together vigorously, letting the friction build lots of warmth, then cover the eyes with the cupped palms and let the eyes relax in the soothing darkness. This practice is called palming.