This is a concentration gazing. It’s a classic meditation technique used to help focus the mind and a useful first step on the mad to deeper meditative practices,

Place a lighted candle at eye level, about 90cm (3ft) away from you.

First regulate your breathing, then start to gaze at the candle without blinking.

Look steadily and softly at the flame, without straining. If your eyes go out of focus, bring them gently back into focus.

When you are ready, close your eyes and keep your inner gaze steady, visualize the object.

When the after-image has gone, open your eyes and repeat the process.