Blepharitis, or eyelid inflammation, one of the most common problems, is characterized by erythematous eyelids with accumulation of debris along the eyelid margin. Malignant eyelid tumors may be associated with lash loss and erosion of normal eyelid structures.
Moon phases depend on the position of both the Sun and Moon with respect to the Earth. The 4 primary phases of the Moon are: new, first quarter, full and third quarter.
Last Quarter-One-half of the Moon appears to be illuminated by direct sunlight. The fraction of the Moon's disk that is illuminated is decreasing. Waning Crescent-The Moon appears to be partly but less than one-half illuminated by direct sunlight. The fraction of the Moon's disk that is illuminated is decreasing. Following waning crescent is New Moon, beginning a repetition of the complete phase cycle of 29.5 days average duration. The time in days counted from the time of New Moon is called the Moon's age. Each complete cycle of phases is called a lunation.