Symptoms may not start for 6 to 12 hours after exposure to the ultraviolet light. Symptoms include: 1  A feeling that something is in the eyes (foreign body sensation). 2  Sensitivity to light (photophobia). 3  Tearing.
It is divided into three stages, called trimesters: first trimester, second trimester, and third trimester. Conception to about the 12th week of pregnancy marks the first trimester. The second trimester is weeks 13 to 27, and the third trimester starts about 28 weeks and lasts until birth.
The first trimester of pregnancy lasts for about the first three months of pregnancy, and is usually the time when a woman realizes that she is pregnant. During the first trimester a woman may experience nausea, extreme tiredness, headaches, mood swings, and several other symptoms.