Abstract: An apparatus (100, 200, 300, 400) for testing a subject's vision and a method of reducing intensity artefacts during a test of a subject's eye (109) are provided. The apparatus comprises: a light source arrangement (102) located towards a source end (104) of the apparatus, and arranged to produce polarized light; and one or more panels (108a, 108b, 108c), the one or more panels comprising one or more blocking regions that do not transmit polarized light, and defining one or more light transmitting regions (111), the one or more light transmitting regions (111) being just large enough to allow unobscured vision by the subject's eye of polarized light travelling directly from the light source arrangement when the subject's eye is positioned adjacent to a viewing end (106) of the apparatus, the one or more panels being located between the light source arrangement and the subject's eye.