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.
The number of eggs a female bird will lay before her clutch is complete depends on several factors: 1  Species: For example, an Eastern Bluebird may lay 4-7 eggs. ( 2 Four or five is most common.) A Black-capped Chickadee typically lays 6-8 per clutch, with as many as 13 reported.he number of eggs a female bird will lay before her clutch is complete depends on several factors: 1  Species: For example, an Eastern Bluebird may lay 4-7 eggs. ( 2 Four or five is most common.) A Black-capped Chickadee typically lays 6-8 per clutch, with as many as 13 reported.