<unk> , Chart 1 There are 7 types of<unk>  charts. All the charts measures 10 cm × 10 cm in size, which can be used to measure central 20 degree visual field when kept at a distance of 33 cm from the eye. Chart 1 Chart 1 is the basic version, which is the most familiar and widely used chart among all the charts. In this chart the<unk>  consists of 0.5 cm squares (each for 1° visual field), which totally measures 10 cm X 10 cm size. Most commonly<unk>  is in white color with black background.<unk>  with black lines in white background is also available (see infobox picture). Chart 2 Chart 2 is similar to chart 1, but it has diagonal cross lines, which assist correct fixation in case of central scotoma. Chart 3 Chart 3 is also identical to chart 1, but color is red on black. Stimulating long wavelength foveal cones, this type of chart may help in detecting color scotomas and desaturation which may occur in toxic maculopathies, toxic optic neuropathies and pituitary tumors etc. Chart 4 Chart 4 has no lines, only a random pattern of white dots in black background. It was intended to differentiate areas of scotoma and metamorphosia. Chart 5 Chart 5 has central white dot and horizontal white lines on black background 5mm apart, which allow detecting metamorphopsia. Chart 6 Chart 6 is similar to chart 5, but lines and central dot is in black on white background. The lines near to fixation points are closer than the chart 5. Chart 7 Chart 7 is similar to chart 1, however central squares are further divided into 0.5 degree squares.
Amsler grid
Haller index
Jaeger chart
Challacombe scale
Mentzer index
Monoyer chart
Lund and Browder chart
Barber–Johnson diagram