The Field Representative's Manual defined a lens implant as an "artificial lens which are surgically and permanently placed inside the eyes, and sometimes referred to as an intraocular lens.

These include:

• CONTACTS Uses contact lenses, 1971, 1979-1981, 1984

• GLASSES Uses eyeglasses (prescription or non-prescription), 1971, 1979-1981, 1984

• GLASSESRX Uses prescription eyeglasses 1984 only

• VDIF Now have trouble seeing even with glasses, 1984 only

• VDIFAMOUNT Amount of vision trouble, 1984 only

• VDIFPEPL2FT Sees enough to recognize people w/in 2 feet, 1984 only

• VDIFSEEFREND Sees enough to recognize friend across street, 1984 only

• VDIFREADNEWS Sees enough to read newspaper, 1984 only

• VDIFSEETV Sees enough to watch TV, 1984 only

• VDIFSTEPCURB Sees enough to step off curb or step, 1984 only

• VDIFREADMAGL Uses magnifying glass to read, 1984 only