Direct sunlight exposure vs indirect sunlight exposure after a hair transplant?

Hello,Sun exposure should be avoided for first 12 weeks.  UV light can damage hair.  More specifically, hair protein degradation occurs at wavelengths of 254nm-400nm, while UVB is responsible for hair protein loss while UVA is responsible for color changes.  On newly transplanted hair, the hair can be damaged by free radicals and photochemical degradation.  
Be safe- 
Anil Shah MD 

The reason why doctors tell you to avoid sun light is because of the ultraviolet light which can cause discoloration.   If you are concerned it is best to contact your doctor.

I recommend wearing a hat for the first 4 months after a hair transplant to help protect the hair grafts from a sunburn.

Indirect sun exposure or even limited direct exposure should not have a significant impact on graft growth.However,as a general health and skin maintenance  rule precautions should be taken to protect  your skin against sun damage.

Although  I dont recommend direct exposure to sunlight for hours between 11 am-15 pm in first 2 weeks of surgery, someone could drive a car without wearing a hat on a cloudy or even sunny day without direct sunlight exposure. 

No problem with sun exposure providing you do not bake in it. If you are going to the beach or plan on spending the day in direct sun, then wear a hat.

Right after a hair transplant when your head is healing, you should avoid additional UV exposure since it just damages the tissues more (and they are already recovering from one insult).  However, after that, and especially after the hair actually GROWS in, you will have less risk to the hair.
It is always a good idea to wear a hat, though.