Everybody reacts differently.
I love longan and it has tonic qualities but does
not suit me. If I take it for two days it affects me negatively. My stomach
will hurt for a whole day and my shoulders and back will ache for a week. Some
people suffer from nose bleeding. People whose body is "hot" are not advised
to take too much longan and need something to cool down their body.
There is something else which is good for eye-sight and suitable for someone who body is "hot". I would like to share with you a method which I learned from someone. I have used it at work for many years. It is really effective, does not consume much time and is as easy as ABC.
Put in a cup a small handful of chrysanthemum tea, rinse with cold water and
hot water and drink it for a whole day. When you finish your first cup you
just continue adding hot water for the following cup. For people who have
sweet tooth, add some rock-sugar .
In addition, foods that contain Vitamin A are good for eye-sight; however, you
can never eat too much and they do have some side-effect. For example, eat too
much carrot may suffer from too much carotene, leading to yellowing of the skin.