Could repeated flinching/seizure-like behavior be associated with eyesight?

Here is a compilation video: https://vimeo.com/434151259

Our 10-year-old toy poodle has begun flinching (for lack of a better word) repeatedly on walks. We’ve been to the vet, but due to an enlarged heart with a leaky valve he wants her to see her cardiologist to ensure it isn’t heart-related. We are trying to get an appointment but the pandemic is making wait times in the weeks and we’re concerned in the meantime about how dangerous waiting could be.

Based on our experience, the flinches rarely happen at home, happen much more frequently in bright sunlight on walks, especially facing the sun. They also occur much more frequently when leaving a shadow into the sun or leaving the sun into a shadow. Her vet has noticed early signs of cataracts and we’ve noticed her eyes getting cloudy. She’s also begun walking into things occasionally.

We’re hoping these are eye-sight related rather than seizures or neurological issues, but are unsure of next steps while waiting appointments with specialists.

Thanks.