Vitrectomy Surgery. updated. Sometimes, a vitreous hemorrhage can clear up on its own. If vision does not improve, vitrectomy surgery may be necessary. A vitrectomy is a surgical procedure that is performed to remove the clouded vitreous gel in the center of the eye.
Hail is generally associated with spring thunderstorms but may occur at any time of year. Hail is formed in huge thunderhead (cumulonimbus) clouds (Munez, 2000). During days when the soil is heated by the sun, the air near the ground also is heated.
Tornadoes can occur at any time of year and at any time of day or  night. They are merely most common in the spring and early summer  and int he late afternoon. In simplest â¦terms, tornadoes most often  occur when a cool air mass collides with a warm, moist air mass,  triggering thunderstorms.