Are women commanded in the laws of Shemiras Eiynayim?
Innocent looking-No pleasure involved: Some Poskim rule that women are to avoid looking at men, just like men are to avoid looking at women. Thus, the women section in a Shul is to be built in a way that the women cannot look at the men. The majority of Poskim, however, negate this view and rule there is no prohibition whatsoever for a woman to innocently stare at a man, even though a man is restricted against gazing at a woman, and so is proven from the Talmud, and so is the final ruling and custom of all Jewry. This applies even if the man is not modestly dressed, such as he is wearing shorts or does not have a shirt, and the like. This, however, is with exception to the Erva area, as explained next.
A sexually stimulating gaze-Pleasure involved: It is Biblically forbidden for a woman to look at the body of a man for the sake of sexual pleasure or arousal, just as is the law by men. Thus, it is forbidden for women to watch movies and the like that contain sexually stimulating scenes. It goes without saying that looking at pornography is a Biblical prohibition both for men and women.
Davening and learning Torah in view of a man whose body is not properly covered: It is permitted for a woman to learn Torah or Daven in the presence of a man whose body is not properly covered [wearing shorts, or no shirt, and the like]. This, however, is with exception to the private area of a man [i.e. the Erva] in which case it is Biblically forbidden to Daven or learn in its presence. The above, however, only applies if seeing the man does not stimulate forbidden thoughts, however, if it does then it is forbidden for her to learn Torah or Daven in his presence.
 See Ohel Yaakov 21:25; Piskeiy Teshuvos 75:3; Dirshu 75:21
 Teshuras Shaiy 1:125 [Seagate], brought in Otzer Haposkim 21 based on Yalkut Shimoni Shmuel Remez 105 brought below
 Setimas Kol Haposkim in O.C. chapter 75; Aruch Hashulchan 75:5; Letter of Rav Yoel Teitalbaum of Satmar, brought in Otzer Haposkim ibid and Tahras Yom Tov vol. 6; Shevet Halevi 5:197 “We have never seen our ancestors and Rabbis suspect for this”; Chut Hashani p. 262; Ohel Yaakov ibiod
 Sukkah 51b that by the Simcha Beis Hashoeiva the women were on top [and would look at the men dancing]; Brachos 20a that Rebbe Yochanon would sit by the Mikveh and women would gaze at his beauty.
 The reason: As the sexual psyche and stimulation of a woman is very different than a man, and we do not suspect that an innocent gaze will lead to forbidden thoughts, in contrast to a man for whom even an innocent gaze can instantaneously turn promiscuous. [See Nida 13a “Nashim do not have Hargasha”; Aruch Hashulchan ibid “By a man there is more worry of Hirhur”; Shevet Halevi ibid]
 Setimas Kol Haposkim in O.C. chapter 75 that there is no Hirhur for a woman to Daven in the presence of a man whose body is uncovered, with exception to the Erva area.
 Yalkut Shimoni Shmuel Remez 105 “Rebbe Yehuda stated that the reason Bnos Yisrael spoke in length with Shaul is in order to gaze at his beauty. Rebbe Yossi said, if so you have turned the Jewish girls into Zonos, as just as it is forbidden for a man to gaze for pleasure at a woman who is not his, so too it is forbidden for a woman to gaze for pleasure at a man who is not hers.”; Sefer Chassidim 614 “A woman should not hear the voice of a man as whatever a man is commanded in so too a woman”; Shevet Halevi 5:197; Divrei Yatziv 5:35; Chut Hashani p. 262; Rav SZ”A, brought in Ohel Yaakov ibid
 The source and reason: As the verse states “Lo Sasuru Acharei Levavchem Viachrei Eiyneichem” from which we learn that it is forbidden to entertain thoughts promiscuity, and there is no differentiation between a man and woman in this command. Thus, looking at a man in a way that stimulates forbidden thoughts is Biblically forbidden. [Shevet Halevi ibid; Igros Moshe Even Haezer 1:69; See Sefer Chassidim ibid] Likewise, it is also prohibited due to the prohibition of Lo Sikrav, as just as a woman is prohibited from doing all the other matters listed in E.H. 21:2 with a man, so too she is forbidden in looking for the sake of pleasure if she is an Erva. Now, although some rule that women are not Halachically relevant to the prohibition of Zera Levatala [See Mishneh and Gemara Nida 13a “Nashim Lav Bnei Hargasha Ninhu” and Tosafus and Tosafus Rosh on Nida ibid], this prohibition applies irrelevant to if it will lead to Zera Levatala as: a) It may lead to sin with that person and b) Looking for pleasure is an intrinsic prohibition, even if it will not lead to Zera Levatal, as sexual interaction with a prohibited relation is Biblically forbidden in its own right, irrelevant of what it does or does not lead to. Likewise, it is Biblically forbidden even for women to think forbidden sexual thoughts. [See Igros Moshe ibid] Furthermore, according to the Mekubalim the prohibition of “Zera Levatala” applies equally to women, and those that do so increase evil spirits and Kelipos. [See Shaar Hakavanos Inyan Drush Layla; Yifei Laleiv 239; Kaf Hachaim 239:3]
 Setimas Kol Haposkim in O.C. chapter 75; Aruch Hashulchan 75:5 [questions this matter but concludes that so is implied from the Poskim and Kesubos ibid]; Piskeiy Teshuvos 75:3
The reason: As women do not have the same level of Hirhur as men. [Kesubos 9; Aruch Hashulchan ibid]
 See Admur 74:1; See M”B 73:5 that a wife may not say Kerias Shema if she is facing her husband unclothed
 Makor Chaim [Chavos Yair] 75; Piskeiy Teshuvos ibid