Can I get covers for these lights?

[sairs_f]

 we have just moved into a new house and the lights are these open downlights. We can see into the roof space. Are there covers we can retrofit onto them? I've replaced a couple of bulbs and they are the screw in type and I can see that the light fitting for the bulb has spring clips to hold it in place. So are there any options other than getting an electrician in to replace every single light in the house?