Monocular Lens
A Color Correction Lens to be worn over one eye, usually as a contact lens. These lenses consist of a simple red (or Magenta) filter. By itself (if worn on both eyes), a red filter cannot correct CVD, but can Hue Shift Colorblindness Tests to introduce a blue-yellow component to Colors of Confusion and make them easier to interpret by red-green Colorblind. The sacrifice is that some colors that were easy to distinguish without the filter, no longer are, but Colorblind Tests don’t use those colors, so simple red filters are a net gain for passing the test.
However, wearing the lens on only one eye gives your two eyes different perceptions, so two colors that look the same in your left eye, may not look the same in your right eye. When the two eyes have different perceptions of color like this, your mind – very must like Depth Perception – can ostensibly use the contradicting information to increase its ability to differentiate colors.
Despite this method existing for over 40 years, they have not been shown to convincingly perform better than a binocular (over both eyes) red filter. However, a binocular filter would interfere with an individual’s Color Naming ability, where a Monocular Lens always leaves one eye with ‘natural’ vision.
There are two types of Monocular Contact Lenses:
