Definition of ophthalmology for English Language Learners. medical : the study of the structure, functions, and diseases of the eye.
Pullet: Six Weeks to One Year. Young female chickens less than 1 year old that have fully feathered out and are about the size of large pigeons are called pullets. Expect your barred rock pullet to start laying eggs when she is about 16 to 20 weeks old. Once she begins laying, she should produce one egg every 25 hours â except during the cold, dark hours of winter when she may not lay at all -- until her first molt a year later.
Each Female Horseshoe Crab lays thousands of small greenish eggs. Horseshoe crabs arrive on the beach, usually at night on a new moon. The female crab digs holes in the beach about 6 inches in diameter and can lay as many as 100,000 eggs at one time.