The conservatory needs a certain amount of furnishing to make it 'livable.' If it is too bright the kids will not be able to see the TV screen. Too hot in summer makes the room inhabitable (staggeringly many people actually remove the internal conservatory door in summer to let the heat out)! Often you will see conservatories built without window vents in the roof apex so the heat becomes trapped. Although there is reflecting glass that can be used to keep the heat down – this won't solve the glare problem though.
So it seems the answer is to get some blinds. Do bear in mind that if you do have a heat issue about 70% of the heat is coming in through the roof. So don't fit window blinds and think that will help – it won't!
When it comes to roof blinds you need to be very cautious when buying them. You have probably heard the stories about the salesman who comes for the evening (sleeping bag in the car)! To sell you your roof blinds, he comes equipped with a bag full of 'discontinued' fabrics to do you a 'deal'. The salesman is prepared to spend as much time with you (many hours in fact) to walk out of your door with an order. DON'T PLAY HIS OR HER GAME.
Lets put this nicely – you have invited the salesman into YOUR house for you to consider buying roof blinds. You should be in control of the situation, you are NOT obliged to entertain him for any longer than you want to and you are DEFINITELY NOT obliged to buy anything on the night. So, yes do make a cup of tea and be civil but do ask lots of questions bearing in mind he or her are prepared to stay all night (because they are on a very big commission). Believe me they would rather spend their evening somewhere else! They are ONLY with you on the prospect of making very good money.
Don't make a decision on the night (you will regret it), do get any free samples and take notes of various prices for different solutions. Then show them the door and arrange to see some other companies, if you haven't already. Get at least 3 quotations and then have a think about the whole service offered – guarantee, how are they fitted (any drilling of your new conservatory!), Reflective material and how much experience do they have (get them to show you their portfolio of previous jobs).
What to ask them when they are with you is in another post.