Modern lenses use lens coatings to reduce the amount of reflection and minimize flare.
i-Fi multi-stage lens coatings filter transmitted light and protect the lens.
In the 1950s, when effective anti-reflective lens coatings became available, coated Planars were produced with much-improved flare.
Crizal is the brand name of optical lens coatings manufactured by French Essilor.
However, with lens coatings at low powers (focal lengths of 20 mm and up) they are acceptable, and at 40 mm they can be excellent.
The super multi-layer lens coating reduces flare and ghosting.
This is done very gingerly, since some of the grime could scratch the lens coatings if pressed too hard.
Special lens coatings provide a sharper image, improved contrast and eliminate glare.
In the years before lens coating was generally practiced, this had advantages for contrast and resistance to lens flare.
Super-Takumar lenses featured an early form of lens coating (to prevent flare) and a more sophisticated stopping-down mechanism.