What is the way to get rid of the feeling of cheating and deception after the husband discovered his wife suffered from a lazy eye after marriage, and what is the ruling of Islamic law on this situation so that his heart may be reassured?

Weakness in one eye does not prevent a husband from enjoying his wife; this is a minor matter. Therefore, you should forget this issue, remove any ill feelings towards your wife's family, and maintain affection, love, and good treatment. Do not allow Satan a path to corrupt your marital life. Praise Allah for the blessing of marriage, for it is one of His signs. Allah Almighty says: "And among His signs is that He created for you from yourselves mates that you may find tranquility in them; and He placed between you affection and mercy. Indeed in that are signs for a people who give thought." Be keen to ensure affection and mercy are present in your family.