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.
Robins usually lay four eggs and then stop. Like most birds, they lay one egg a day until their clutch is complete. If you remove one egg each day, some kinds of birds will keep laying for a long time, as if they can stop laying only when the clutch of eggs feels right underneath them. Robins normally lay four eggs.