Better to Use Revitalash Than Latisse to Avoid Side Effects?

These are two different things.Revitalash is an eyelash conditioner that claims to make your lashes appear fuller, (think conditioner for your hair). It is not a medicine. It does not have FDA approval. As of this writing, there are no clinical, scientific trials published in a peer reviewed medical journal.Latisse consists of an established medicine that has been used for years to treat glacoma. They found some glaucoma patients had significant eyelash growth. Allergan configured it to be a topical medicine for eyelash growth. They went through the rigors of FDA approval. The science says that it keeps the lashes in growth phase. Clinical trials showed that it can lengthen eyelashes 25% and thicken them 106%, later with more use, and will darken them.   There was some reports that with the eye drops, if you had hazel eyes with brown spots, the brown spots may get more brown.  It should not change your blue eyes.  as of this writing, there has been no color changes when using latisse.

Both are the same in their potential risks, and will give you similar results.
I believe both has the same active ingridiednts but Revitalash will not say that.

The active ingredient in Latisse which grows lashes is Bimatoprost, a prostamide, a prostaglandin analog which lowers eyeball pressure in patients with open-angle glaucoma. When patients using Lumigan eyedrops for glaucoma began having longer lashes a lot of doctors began prescribing the medication to people who did NOT have glaucoma -- for cosmetic reasons.
Several make up companies, including Jan Marini Skin Age Intervention Eyelash Conditioner, Athena Cosmetics Corp. - RevitaLash, MassiveLash, and MD Lash Factor , began selling eyelash products allegedly secretly containing Bimatoprost, the active ingredient in Lumigan®. Allergan, the maker of Lumigan and owner of the license to Bimatoprost sued them for millions and the cases were settled with these companies promising to remove the Bimatoprost from their products. Therefore, Revitalash no longer contains Bimatoprost and does not compare to Latisse in effectiveness.
Applied to the edge of the upper lid without direct application to the eye means you have a VERY small risk of eye color changes.