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 is week 1 through to the end of week 13. The second trimester usually ends around the 26th week and consists of the 4th, 5th and 6th completed months. The third trimester can end anywhere between the 38th - 42nd week and is the 7th, 8th and 9th completed months of pregnancy.