GRADIENT DENSITY SUNGLASSES.
Abstract
This report details the effort expended on design, fabrication and delivery of 91 pairs of Gradient Density Sunglasses. Lenses having a neutral absorbing base with a nominal density of 0.52 and lenses having a clear base were coated with a gradient layer of titanium suboxide and antireflected by a uniform film of magnesium fluoride to produce neutral gradient density sunglasses. Within acceptable limits, the density varied linearly from about that of the uncoated substrate at the bottom of the lens to 2.5 = 0.3 at the top of the lens. The coatings were deposited on the concave surface of all lenses, and the contra-ocular surface remained uncoated. The back reflectance measurements that were made on a number of lenses averaged the reflectance over an area 12 mm in diameter. The reflectance minima measured varied from 1% to 3% over the various areas of lenses from different production cycles, and if the minimum was located between 500 and 600 millimicrons, the reflectance could rise to about 8% at 400 millimicrons and 6% at 750 millimicrons. The coatings passed the JAN-F-675 abrasion test and the specified scotch tape test. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1964
- Accession Number
- AD0608299
Entities
People
- Helen Jupnik