(Self-advice) Either with closed or open eyes, just try to see the most merciful syllables of निताइ's name and nothing else. Don't engage your eyes in seeing any other beautiful object, person, or scene. Otherwise you won't be able to see the syllables of Nitai Nam clearly. It is up to you now. What do you really want to see?
The bigger you write the निताइ Nam Akshar Parabrahm, the better you can visualize. And better visualization means greater ecstasy and deeper absorption.
Caitanya Mahāprabhu has said,
sādhu-saṅga sādhu-saṅga sarva-śāstre kaya
lava-mātra sādhu-saṅge sarva-siddhi haya
(CC Madhya 22.54)
Here Sadhu refers to Nitai (the topmost Sadhu) and Sanga is possible by Vayulekhan. So Sadhu Sanga means Nitai Vayulekhan. Therefore, Nitai Vayulekhan can grant all perfection (sarva-siddhi) instantly (lava-matra).
Kali Yug is highly ironical. On one hand, it is almost impossible to have Sadhu-sanga as there are no real Sadhus in this degraded age. And on the other hand, there is a golden opportunity to touch, embrace, and serve the topmost Sadhu (Nitai) by the simple process of Nitai Vayulekhan. What an irony!
Nitainam Lekhan is that Sadhana which leads to spontaneous remembrance even in those circumstances in which remembrance is very difficult.
Nitainam Lekhan nourishes the spiritual intelligence. As a result we are practically able to accept things favorable to devotional service and reject things unfavorable to devotional service much more effectively.