Unique Vintage Sliding Frame Eyeglasses. Says Pat Pend On Bar. Lens is 1.75" Wide,1" Tall. Belonged to step grandmother from Lakeview, OR. Case label shows from Columbian Optical Co. She would have purchased them from the Klamath Falls OR office. Lens and case in excellent condition. Not sure of the year they were made. Maybe mid 1900s?