Simulates astigmatism in one meridian (e.g., simple myopic astigmatism). In minus cyl, blur is 90 degrees perpendicular to the axis and in plus cyl blur is on the same meridian as the axis.

Vitreous opacities that can drift across the visual field (animated).

Persistent flickering static across the entire visual field (animated).

Binocular diplopia gives two distinct images (resolves when one eye is covered); monocular gives a fainter overlapping image.

Loss of central vision that can occur with conditions such as macular degeneration.

Color fringing at high-contrast edges as wavelengths focus at different points. This can occur when looking off-axis through a lens, especially if the lens material has a low Abbe value or the lens is a high power.

A localized patch of distortion: straight lines appear wavy in one paracentral area, as in macular disease. Best seen on the Amsler grid.

Constricted peripheral vision (e.g., advanced glaucoma, retinitis pigmentosa). It should be noted that loss of peripheral vision does not necessarily appear dark as it does on the simulator but is rather missing and may be hard to notice.