Image - Eye chart

Some images of watches, and the mechanical structures within them. I intent on drawing very detailed illustrations of watches, varying from a range of styles and ages. When using them within the eye test structure, the detailed illustrations will be based at the top, in which they can be large (to have the ability to see the detail) and smaller, less detailed, almost icon like drawings will be placed towards the bottom on the eye test on a smaller scale.

This, is primarily, what i want to achieve within my eye test. Using biro to create very crisp, precise, detailed illustrations on a browned stock.

The style of illustration I would like to achieve.

Eye Charts

The various layouts mean I'm quite free into the composition choice.  Whether it be triangularly, or in lines scaling down in size throughout.

Some examples of images within an eye test chart

The below image a pocket watch in the style of pop art, again a different approach I could take, but I feel the limited colour palette means this style to be inappropriate. But if there was an unlimited colour palette I could take into consideration the colours used within the Ishihara Colour Vision Test. These colour be used appropriately as a part of the eye test chart I will produce.

Colour perception

The images below are part of the "Ishihara Colour Vision Test" , developed by Dr. Shinobu Ishihara.

All sighted people should see the number 12 in the first circle. People with normal colour perception should see the numbers 2, 5, 6, 7 in the following four circles.

More About Colour Perception

There are two types of vision sensors in the human eye: Rods (which see black and white) and cones (which see colour).

Rods are more sensitive than cones, which is why we don't see colours well in the dark.

There are three types of cone: Red, green and blue. If a person has a lack of one or more type of cone, or if the cones are defective, colour perception will be affected.

"Colour Blindness" is not an accurate term, as most people can still perceive colours - just to a lesser extent. "Colour Vision Deficiency" is a more accurate description.

Most colour perception defects are for red or green or both. Yellow-blue defects can also occur, but very rarely. Complete absence of colour perception (i.e. black and white vision) is extremely rare.

Colour vision deficiency affects about 10% of males and less than 1% of females. The most common cause is hereditary.