I have been using Katseye Blends for many years after being introduced to them during my training for ear candling.
I am a fully trained aromatherapist and largely prefer to blend my own oils, but often buy unblended oils and some of the blends too from Katseye (Chris Katsis). I personally haven't done the Katseye training, but if I wasn't an aromatherapist, I might have considered it.
The Katseye Concept is a range of blends of essential oils (but not blended in carriers) for use by aromatherapists or those trained in the use of Katseye Blends. The advantage being that maybe six or eight oils may be present in a blend in varying proportions that the aromatherapist would not be able to achieve with a smaller amount of oil. Whether you attend training or not, therapists can access an online manual of the different blends and their uses.
I know Chris has used a biochemist in the preparation of these blends and I can vouch that they are of the highest quality. Most of my clients are cancer patients and I am very picky about the oils I use.
Just to confirm that I have nothing to do with the company or nothing to gain, but am just a satisfied customer.