Quite often when using a commercial potting mix, the trasparent balls can be the empty capsules from the slow release soluble fertilizers they added during manufacture.
Otherwise you will need to photograph the balls and post pictures for identification.
If they are perfectly clear and round, my bet is on the fertilizer capsules theory, but if they are cloudy or opaque and a bit random in shape, then yes, they could be insect eggs, perhaps snail/slug eggs, but pictures for ID would be needed.
Generally all commercial mixes are sterilized with steam prior to sale to ensure there are no insect eggs or weed seeds.
Also, insect eggs will usually be clustered in a small area, whereas fertilizer capsules will be distributed randomly throughout the soil.
Spider mite eggs will be in the leaves and be microscopic dots.
Hope this helps, Organoman.