An optical system having a transmission pattern comprising at least a first zone Z1 extending from at or about 380 nm to a first limit L1 between Z1, and a second zone Z2. A third zone Z3 extends from a second limit L2 between Z2 and Z3 to about 780 nm. L1 may be greater than or equal to or about 436 nm. Second limit L2 may be greater than L1 and smaller than or equal to or about 487 nm. The average transmission values T1, T2, T3, in each zone Z1, Z2, Z3 may be: T2>5*(T1+T3)/2, with T1 the average transmission over Z1, T2 the average transmission over Z2, T3 the average transmission over Z3. T1 and T3 may be greater than or equal to or about 3% and smaller than or equal to or about 70%. T2 may be greater than or equal to or about 75%.