Begin by drawing two circles, representing the eyeballs. A hard pencil should be preferred to use for this purpose and ample space need be kept between the two circles.
Now you have to draw the pupil of the eye, making a 9-centimetre small circle within the almond shapes. The size of the pupil depends upon the dimensions of the eye and the mood you are trying to depict. Larger pupil is a symbol of excitement, whereas smaller pupil represents age or fear.
Now draw a border around the pupil to make the iris of the eye. You have to use the pencil very gently and need not to press it too hard on the drawing surface.
Next, draw the eyelids around both circles and ensure to curve the eye lids around the edges to give them a natural look.
You need to shade the eye lids for bringing the natural look to them. Make shadows around the edges of the eyeballs, highlighting the peak portion of eyelids just above the iris.
You have to add shades to the eye lids according to the skin complexion of the face. Make sure to choose a bit darker shade for the lower eyelid to keep your drawing more realistic.
You have to add striation radiating from the centre of pupil out towards the edges. You better use slightly darker shade for this striation than the colour of the pupil. You can choose any colour of your choice.
Paint the pupil of the eye black and draw a thin black line around the iris.
Drawing tiny veins on the white area around the iris will bring more natural look in your painting. These veins also depict fatigue, age or sickness.
Highlighting the pupil and iris with white colour will represent light falling on the eyes.