This week is appropriate to learn about shmiras einayim for several reasons. This past Shabbos, Parshas Behaloscha, we read about the kindling of the menorah. Likutei Mohoran (21, 2) explains that the face has seven candles, like a menorah, and need to be used properly. Two of the candles are the eyes, which we need to guard from seeing inappropriate things. (The other five candles are two ears, two nostrils and the mouth.) In the coming parsha, Shelach, we have the posuk וְלֹא-תָתוּרוּ אַחֲרֵי לְבַבְכֶם וְאַחֲרֵי עֵינֵיכֶם אֲשֶׁר-אַתֶּם זֹנִים, אַחֲרֵיהֶם And you shall not run after your heart and after your eyes, which you will use to go astray. Rashi quotes the medrash saying that "the eyes see, the heart desires and the body sins".
There is a prohibition to look at women dressed improperly, and it is also prohibited to look at even the little finger woman, if done for pleasure. While everyone knows that it is forbidden to look at a woman who doesn't cover everything required by halacha, one has to remember that even if a woman is dressed properly, looking at her for pleasure is completely forbidden. These are not chumras, but simple halacha. Also, if a man has another woman, besides his wife, in his mind, it can cause his children to be like mamzeirim, on a spiritual level. (I didn't want to scare anyone off with what the seforim hakedoshim say happens to one who is not careful with shmiras einayim. For those interested, among other seforim, see Kav HaYosher Chapter 2 who quotes the Zohar on this.)
Yetzer Hora Is Stronger In The Summer
Although shmiras einayim is relevant all year, it is even more so in the summer months. Perhaps that's why Parshas Behaloscha and Shelach, where we learn out the aforementioned things, are at the beginning of the summer months.
In Parshas Shelach (13, 20) it says וְהַיָּמִים-יְמֵי בִּכּוּרֵי עֲנָבִים the time was of the first-ripe grapes. This is referring to the time when the meraglim (spies) went on their mission. The Chida says in the name of Reb Shimshon Ostropolier that if you take the letter before each letter of עֲנָבם, it spells סמאל, the satan. (We take each letter before because בִּכּוּרֵי עֲנָבִים can be interpreted as "before עֲנָבִים". The Chida explains why the "yud" isn't used here. עֲנָבִים is written many times without a "yud".) The samech mem is stronger than usual in the months of Tamuz and Av, as these months are Esav's months; that's why the incident of the meraglim happened then. (Pnei Dovid)
To add to this, Rashi on the posuk וְלֹא-תָתוּרוּ אַחֲרֵי לְבַבְכֶם וְאַחֲרֵי עֵינֵיכֶם says that the eyes are called meraglim. This fits in well, since we know that shmiras einayim is more difficult in the summer. Just like satan was able to bring about the incident of the meraglim, as written before, so too, he causes the other meraglim, the eyes, to sin, in the summer.
Gateway To The Neshama
The eyes are a gateway to the nishama. That's why, interestingly, the eyes are the only part of a human being that gets affected by even the smallest speck of dirt. We all know how annoying and uncomfortable it is when a small hair or speck of dirt gets in the eyes. This helps us understand a little how any speck of "dirt" on the nishama greatly damages it. There is terrible damage caused by looking at improper things. One should not look at the face of an evil person or stare at impure things, but the biggest problem faced is seeing women dressed immodestly or looking at them for pleasure.
The Eyes Don't See What The Heart Doesn't Desire
When Reb Ahron, the son of Reb Yehoshua of Belz got engaged, the Governor of the town announced that he was coming with the Governess to congratulate the Rabbi and his son. Reb Ahron asked his father what he should do about having to meet with the Governess, as he might have to look at her. Reb Yehoshua told his son that the Medrash quoted by Rashi (as mentioned above) says that the eyes see and the heart wants, but the posuk mentions the heart before eyes. The reason why this is, the Rebbe explained, because if the heart doesn't desire then the eyes don't see.
The Unavoidable and What To Do
One needs to put in his best efforts to avoid seeing the forbidden. The Rebbe Reb Elimelech of Lizensk says the following in Tzetel Koton:
One shouldn't look out of their four cubits, and if one does see a woman he should imagine the name א־ד־נ־י in front of his eyes. (# 5)
If one sees a mokom ervah of a woman he should say the posuk וְלֹא-תָתוּרוּ אַחֲרֵי לְבַבְכֶם וְאַחֲרֵי עֵינֵיכֶם (# 7)
After putting in one's best efforts, the best segula against seeing forbidden thing is to daven to Hashem for help in this matter, either in your own words or with tefilos from Likutei Tefilos (P. 641-647 in this version)or other seforim that have tefilos for Shmiras Einayim. Kav HaYosher (Chapter 2) writes that Dovid HaMelech says in Tehilim (119:37) הַעֲבֵר עֵינַי מֵרְאוֹת שָׁוְא turn my eyes from seeing vanity. שָׁוְא is the gematria of שז which stands for שכבת זרע. With this allusion, the posuk reads: turn my eyes from seeing things that can cause שכבת זרע. The Tur in the very first section of Orach Chaim mentions this posuk and says that one should constantly daven that posuk.
Walking in the streets of just about any neighborhood, one will come across things he shouldn't see. Reb Moshe of Kobrin says that for the first look, which is unintentional, one doesn't get punished, however if one looks a second time, intentionally, he gets punished for that.
The Beis Yisroel of Ger said that if one is walking in the street and happens upon an immodestly clad woman, as long as he keeps going and doesn't think about it he won't be held accountable. (My understanding is that we are not angels and if we see, fine, and move on, not thinking about what happened.)
If one has bad thoughts and is able to conquer them, then Hashem has great pleasure from that. If one does find himself thinking about what he saw, instead of fighting a battle trying to extricate the thoughts from the mind, which will only cause them to become even stronger, just think about something else, such as Torah, Avodah or even business, because it isn't possible for two thoughts to occupy the mind at once.(Likutei Mohoran 233)
Staying up all night Shevuos, saying Tikun Leil Shavuos, s a tikun for the forbidden things one has seen with his eyes. (Pele Yoetz, Moed L'Kol Chai)
Why the Rebbe of Lublin was called the Chozeh
If one has "kosher" eyes he will be able to see lofty things that the eyes normally can't see. (Likutei Mohoran 254)
When the Reb Yaakov Yitzchok of
When he reached of age a fine shidduch was found for him. He did not look at his kallah until the wedding, as he had no need to see her until the wedding. At the wedding, he opened his eyes to see his soon to be wife, and saw a graven image on her face. He immediately told his father that the wedding has to be called off. They were, understandably, very angry at him. The girl supposedly had all the qualities anyone would want. But, he knew what he saw on the girls face and had no choice, but to call off the wedding.
From all those years of not looking at anything improper he was able to see things that the regular eye couldn't perceive. The rest is history. He found a proper match and went on to be called the Chozeh, the Seer, because he could see from one end of the world to the other, due to his protecting his eyes from seeing the forbidden.
The Woman's Responsibility
This is not the place to talk about tznius-that's a separate issue, but women have to make sure that they dress appropriately, so that they shouldn't cause men to sin by staring at them. If a woman is dressed modestly, and a man chooses to look at her, that's his problem. However, if a woman dresses with immodest clothes, causing men to look at her, then she is causing others to sin. Unfortunately, in recent years, there are stores owned by frum people in frum neighborhoods, selling clothes to frum people that are extremely provocative in nature. There is no need to get into details and these are not chumras by any stretch of the imagination. Enough said.
While it is an obligation not to look at the forbidden and one will get reward in Olam Habah for it, there are segulas brought down from tzadikim, that work when one is careful with shmiras einayim. Here are some, from Segulas HaBaal Shem Tov V'Talmidov:
Reb Uri "the Saraph" of Sterlisk says his children will live and will be able to be raised without pain
Sefer Yisroel Kedoshim says he will be protected from ayin hora, because ayin hora can only affect one who damages his eyes by looking at the forbidden.
Reb Ahron Roth, the Shomer Emunim, says when someone walks on the street and guards his eyes in is considered a very important thing in Heaven. If one walks on a small street and guards his eyes, it is considered as if he learnt a small Mesechta. If he walks on a big street and guards his eyes, it is considered as if he learnt a big Mesechta. (Imagine all that gemara to your credit.)
There is a kabalah passed down from the Vilna Gaon, which is also said by Reb Ahron Roth. If one comes across a forbidden sight, and conquers his yetzer hara and doesn't look, it is a shaas rachamim, a time of mercy from Heaven, and whatever one davens for at that time is mesugal to be accepted. Similarly, R' Yehudah Tzadka related that one of big Rabbonim asked Baba Sali why his own tefilos were not answered, but when Baba Sali davened, Baba Sali is answered. Baba Sali answered: "because I guard my eyes and mouth".
Encouragement For The Future
Whatever level one is on there is a possibility for improvement. Even if you are one that purposely looks at the forbidden, it is never too late to work on yourself. Reb Nachman of Breslov and others have said that one can never give up, no matter how low he has sunk. There is always a way to return, and the further away you are, the more "enjoyment" Hashem has from it. Imagine that, someone decides to try in some small way to improve his shmiras einayim, and you actually give enjoyment to Hashem. And if you try, and fail, get up and try again and again. The harder it is the more enjoyment to Hashem and you WILL succeed in the end. If one sincerely tries he is helped from Above.
For those interested in more on this topic, there is is a sefer called Kedushas Einayim, by Rabbi Toisig, that covers everything having to do with the eyes.