Visual system

A visual system, comprising a lens barrel, and a lens group and a spacing element group assembled within the lens barrel, wherein,

• the lens group comprises, arranged in sequence along an optical axis from a first side to a second side:
• a first lens having a positive refractive power, a reflective polarizing element, a first quarter wave plate, a second lens having a negative refractive power, a third lens having a refractive power, a partially reflective element, a second quarter wave plate, a polarizer, and a fourth lens having a refractive power;
• the spacing element group comprises:
• a first spacing element disposed between the first lens and the second lens and against a second side surface of the first lens, a second spacing element disposed between the second lens and the third lens and against a second side surface of the second lens, and a third spacing element disposed between the third lens and the fourth lens and against a second side surface of the third lens;
• wherein, a number of lenses having refractive powers in the lens group is four;
• a spacing EP01 from a first side surface of the lens barrel to a first side surface of the first spacing element along the optical axis and a center thickness CT1 of the first lens on the optical axis satisfy:
• 1.0<EP01/CT1<1.7;
• and
• an inner diameter dos of the first side surface of the lens barrel and a radius of curvature R1 of a first side surface of the first lens satisfy:
• 1.75<d0s/R1<2.3.